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Application Applicant 5/26/2023
City of Springfield Development & Public Works 225 Fifth Street Springfield, OR 97477 Floodplain Overlay District Development SPRINGFIELD #A/ Required Project Information (Applicant. complete this section) Applicant Name: Olaf Sweetman Phone:(`�1) 682-6424 Company: Lane County Public Works Email: Olaf.SWEETMAN@lanewuntyor.gov Address: Engineering & Construction Services 3040 N Delta Highway Eugene, Oregon 97408 Applicant's Re .:Angela Martinec, PE Phone: (503) 221-1131 Company: Harper Houf Peterson Righellis Inc. Email: angelam@hhpr.com Address: 205 SE Spokane Street, Suite 200 Portland, OR 97202 Property Owner: Olaf Sweetman Phone: (541)682-6424 Company: Lane County Public Works Email: Olaf.SWEETMAN@lammuntyor.gov Address: Engineering & Construction Services 3040 N Delta Highway Eugene, Oregon 97408 ASSESSOR'S MAP NO: 17032711 TAX LOT NOS :2300, 2400 Property Address: 2150 - 2186 Laura Street, Springfield, Oregon 97477 Size of Property: Disturbed area ^ 0.25 acres Acres M Square Feet ❑ Zonin : Low Density Residential Existing Use: Existing 36" concrete stormwater drainage pipe that conveys Channel 6 under Laura Street Description of If you are filling in this form by hand, please attach your proposal description to this application. Proposal: The project will replace the existing 36 -inch concrete stormwater drainage pipe with a 4 Si natures: Please sign and print your name and date in the appropriate box on the next Pace. Required Property Information (City Intake Staff., complete this section) Associated Cases: Case No.: Date: 5/26/2023 Reviewed by: Application Fee: $ Technical Fee: $ Posta a Fee: $0 TOTAL FEES: $ PROJECT NUMBER: Revised 3/9/22 Sandy Belson 1 of 4 Signatures Owner: The undersigned acknowledges that the information in this application is correct and accurate. re Print Date: 5/26/2023 not the owner, the owner hereby grants permission for the applicant to act Date: 5/26/2023 Signature Kristi Krueger Revised 3/9/22 Sandy Belson 2 of 4 Signatures Owner: The undersigned acknowledges that the information in this application is correct and accurate. re Print Date: 5/26/2023 not the owner, the owner hereby grants permission for the applicant to act Date: 5/26/2023 Signature Kristi Krueger Revised 3/9/22 Sandy Belson 2 of 4 Floodplain Overlay District Development Application Process 1. Applicant Submits a Floodplain Overlay District Development Application to the Development & Public Works Department The application must conform to the Floodplain Overlay District Development Submittal Requirements Checklist on page 4 of this application packet. Planning Division staff screen the submittal at the front counter to determine whether all required items listed in the Floodplain Overlay District Development Submittal Requirements Checklist have been submitted. Applications missing required items will not be accepted for submittal 2. City Staff Conduct Detailed Completeness Check • Planning staff conduct a detailed completeness check within 30 days of submittal. • The assigned Planner notifies the applicant in writing regarding the completeness of the application. • An application is not deemed complete until all information as required by SDC 3.3.435(B), including all information necessary to evaluate the proposed development, its impacts, and its compliance with the provisions of the Springfield Development Code and other applicable codes and statutes have been provided. • Incomplete applications, as well as insufficient or unclear data, will delay the application review process and may result in denial. 3. City Staff Review the Application and Issue a Decision • Floodplain development approval is a Type I decision and thus is made without public notice and without a public hearing since there are clear and objective approval criteria and/or development standards that do not require the use of discretion. • Decisions address all the applicable approval criteria and/or development standards. • Applications may be approved, approved with conditions, or denied based on the findings of fact showing compliance/non-compliance with the floodplain development standards in SDC 3.3.430. • The City mails the applicant and any party of standing a copy of the decision, which is effective on the day it is mailed. • The decision issued is the final decision of the City and may not be appealed. 4. Next Steps • Approval of a floodplain development permit is required before construction or development begins within any area of special flood hazard established in SDC 3.3.420(B). Upon placement of the lowest floor of a structure (including basement) but prior to further vertical construction, applicant must obtain documentation, prepared and sealed by a professional licensed surveyor or engineer, certifying the elevation (in relation to mean sea level) of the lowest floor (including basement). • Where base flood elevation data are utilized, the applicant must obtain As -built certification of the elevation (in relation to mean sea level) of the lowest floor (including basement) prepared and sealed by a professional licensed surveyor or engineer, prior to the final inspection. Revised 3/9/22 Sandy Belson 3 of 4 Floodplain Overlay District Development Submittal Requirements Checklist NOTE: If you feel an item does not apply, please state the reason why and attach the explanation to this form. ❑ Application Fee - refer to the Development Code Fee Schedule for the appropriate fee calculation formula. A copy of the fee schedule is available at the Development & Public Works Department and on the city's website. The applicable application, technology, and postage fees are collected at the time of complete application submittal. City to determine/provide ❑ Floodplain Development Application Form ❑ Property Ownership or Control - a copy of the deed to the property, present lease agreement, or other evidence showing the applicant is exclusive ownership or control of the property, or has consent of all owners to act on their behalf. City and County to provide ❑ Narrative explaining the proposal and any additional information that may have a bearing on the action to be taken, including findings demonstrating compliance with the Floodplain Overlay District Development Standards described in SDC 3.3.430. Hydraulic Report ❑ Three (3) Copies of a Plot Plan drawn to scale to include: ❑ The nature, location, dimensions, and elevations of the development area ❑ Name, location, and dimensions of all existing and proposed structures ❑ Name, location, and dimensions and amount of fill and/or excavations ❑ Name, location, and dimensions of all storage of materials 60% CD Plan Set and ❑ Name, location, and dimensions of all drainage facilities Hydraulic Report ❑ Base flood elevation area ❑ Elevation in relation to mean sea level ❑ Of the natural grade(s) of the proposed development area (for structures, show elevations at the corners of the proposed structures) prior to excavation or the placement of fill ❑ Of the lowest floor (including basement) of all structures and all attendant utilities of all new and substantially improved structures (in accordance with SDC 3.3.425(C)(2) ❑ To which any structure has been flood -proofed ❑ Other Permits - Copies of required local, state, and federal permits Refer to JPA ❑ Floodproofing Certification - Provide certification by a registered professional engineer or architect licensed in the State of Oregon that flood -proofing methods for any non- residential structure meet the flood -proofing criteria for non-residential structures in SDC 3.3.430(B)(3)(c). N/A ❑ Floodway - Certification by a registered professional engineer demonstrating through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that proposed encroachment(s) will not result in any increase in flood levels within the community during the occurrence of the base flood discharge (unless a CLOMR is approved by FEMA). Hydraulic Report ❑ Watercourse - Description of the extent to which any watercourse will be altered or relocated. Hydraulic Report ❑ Base Flood Elevation data for subdivision proposals or other development when required per SDC 3.3.425(C)(1) and SDC 3.3.430(A)(7) Hydraulic Report ❑ Substantial Improvement Calculation for any improvement, addition, reconstruction, renovation, or rehabilitation of an existing structure N/A Revised 3/9/22 Sandy Belson 4 of 4 I i LI II I I I I �/"' EXISTING FACE OF BUILDING,TlP. - DITCH EXCAVATION ASSUMED = 67 CU YDS + JED PAO V%� GI Nss/0'? 77,944 `�� ORF.G06 _ �gUJ.BPPMP EXPMS: 12/31/2023 DATE EXISTING DRAINAGE o I}II CHANNELWIDTH EXISTING BOTTOM OF DRAINAGE CHANNEL 1 FLOODPLAIN BOUNDARY, TYPICAL I 1 `EXISTING PROPERTY LINE, TYP. v I f -54m I f 5knl I— �� EXISTING EASEMENT, TYP, PROPOSED TCE, TYP. PROPOSED R/W, TYP. EXISTING R/W, TYP. �\ REV61ON FLOODPLAIN EARTHWORK ANALYSIS CUT (CU. YDS) NET (CU. YDS( 169.12 118.82 50.3 (CUT( APPR D LAURA STREET UPGRADE SPRINGFIELD, OREGON LANE COUNTY FLOODPLAIN ANALYSIS - EARTHWORK EXHIBIT FLOODPLAIN BOUNDARY, TYPICAL V DESIGNED: HHPP REVIEWER: RJR CHECKED: N4W DRAFTER: HHPR DATE s EET sHEFT NO. 04/1e/2023 of 1.0 Channel 6 Crossing at Laura Street Final Hydraulic Analysis Report Prepared For: Lane County Prepared By: Angela Martinec, P.E.—Hydraulic Engineer Allison Race, P.E.—Hydraulic Engineer May 2023 ��QED PROpFs �5 c t N e sio Harper e� F�T'.ofis HP Houf Peterson �-� Righellis Inc. s U EE.. PLANNERS �,, �....E�.=.,.. C2s.�°° 4 ti1ARIEMPQ' 205 SE Spokane Street, Suite 200 Portland, OR 97202 ph: 503-221-1131 fax: 503-221-1171 / y) iN�bj- a( d I b i Prepared For: Lane County Prepared By: Angela Martinec, P.E.—Hydraulic Engineer Allison Race, P.E.—Hydraulic Engineer May 2023 ��QED PROpFs �5 c t N e sio Harper e� F�T'.ofis HP Houf Peterson �-� Righellis Inc. s U EE.. PLANNERS �,, �....E�.=.,.. C2s.�°° 4 ti1ARIEMPQ' 205 SE Spokane Street, Suite 200 Portland, OR 97202 ph: 503-221-1131 fax: 503-221-1171 Channel 6 Crossing at Laura Street Final Hydraulic Report Table of Contents Topography............................................................................................................................... 4 100 -year Peak Flow Results.....................................................................................................4 FlowComparison......................................................................................................................5 Fish Passage Considerations.......................................................................................................6 RegulatoryStandards...................................................................................................................6 Floodplain Development Regulations.......................................................................................6 DesignApproach..........................................................................................................................7 Design Objectives and Constraints...........................................................................................7 DesignFlows............................................................................................................................8 DesignSlope.............................................................................................................................8 ChannelAlignment....................................................................................................................9 ChannelShape.........................................................................................................................9 PredictedHydraulics.....................................................................................................................9 NoRise................................................................................................................................... 10 Conclusion.................................................................................................................................. 12 Channel 6 Crossing at Laura Street Final Hydraulic Report Project Summary Lane County is proposing to upgrade approximately 1,300 lineal feet of Laura Street, starting at the private Monts Loma mobile home park entrance, located approximately 320' north of the existing ODOT entrance, to approximately 250' north of Lindale Drive. Upgrades are related to much needed pedestrian, bicycle, and vehicular safety improvements. The widening of Laura Streetwill accommodate a continuous bike lane and sidewalks on both side of the road. Additional improvements include franchise utility relocations and connections, street lighting, ADA ramps, driveway connections, landscaping, striping, and stormwater improvements. Included in the stormwater improvements is an upgrade to the existing 36" diameter culvert conveying Channel 6 under Laura Street. Following project completion, the County plans to transfer the Laura Street right-of-way ownership to the City of Springfield. The County proposes to upgrade the existing 36" diameter culvert under Laura Street to provide hydraulic capacity for the future 100 -year peak storm flow within Channel 6, without causing a rise in the surface water elevation. Channel 6 is a tributary to the 1-5 and O Street Canals which carry overland flow to ultimately discharge to the 1Mllamette River. In 2014, AMEC Foster Wheeler Environment & Infrastructure, Inc. (AMEC) finalized the Channel 6 Stormwater Master Plan for the City of Springfield. The purpose of the study was to evaluate flooding along Channel 6 and identify capital improvement projects (CIPS) that could improve the conditions in problem areas. In 2017 that study became the basis for a detailed hydraulic study and preparation of a Letter of Map Revision (LOMR) for Channel 6 which had previously not been studied in detail. The purpose was to meet FEMA mapping requirements and help the City better evaluate CIPS. The 2014 study created a model of Channel 6 using the US Environmental Protection Agency program SWMM to analyze the hydrology and hydraulics of the existing pipe and open channel geometry of the conveyance network. This model was used to develop a HEC -RAS hydraulic model during the preparation of the 2017 LOMR study. The CIPS that had been recommended in the 2014 Master Plan were reevaluated with the new LOMR model using an iterative process of modeling improvements along the channel and evaluating the effects on localized flooding areas. Page 1 Channel 6 Crossing at Laura Street Final Hydraulic Report Improvements were made from upstream to downstream in the model as upstream improvements result in higher flow rates downstream. Seven CIPS were recommended along the length of the channel in AMEC's 2017 Channel 6 Recommended Capital Improvement Projects letter to the City of Springfield. It was recommended that they be constructed from downstream to upstream so that downstream areas would have adequate capacity to convey upstream flows once upstream improvements are completed. Upgrading the existing culvert under Laura Street was recommended as CIP 5 in the 2017 recommendations letter. Refer to the 2017 CIP letter attached in Appendix D. The CIP 5 improvement will increase the capacity of the pipe under Laura Street to accommodate the future CIP 6 upgrade. CIP 6would convert the 36 -inch pipe upstream from the Laura Street culvert to an open channel which will reduce flooding in the vicinity of Laura Street and decrease the tailwater elevation at the Pioneer Parkway outfall which contributes to flooding in the 100 -year event upstream of Pioneer Parkway. Along with the Laura Street Upgrades project, the segment of 36 -inch pipe referred to as CIP 5 in the Recommended Capital Improvements letterwill be increased in size in order to accommodate a future improved upstream condition which will reduce flooding at Laura Street and upstream of Pioneer Parkway. The effective FEMA HEC -RAS model which was used in the 2017 LOMR will be used to analyze the improvements. Additionally, hydraulic analysis results documenting a'No Rise' condition using the HEC -RAS program have been performed and are included in this final report document. Site Investigation A hydraulic site walk was performed by HHPR in October 2022. Existing stormwater facilities in the vicinity of Laura Streetwere located and photographed. The existing channel up and downstream of the improvement area was photo documented as well as a tributary area to the south and Pioneer Parkway culvert outfalls to the east. Site information gatherwas used to check groundcover, conveyance elements and existing conditions for use in the analysis and design of the proposed culvert and supplement the existing hydraulic model where relevant. Page 2 Channel 6 Crossing at Laura Street Final Hydraulic Report Hydrology A hydrologic analysis was performed to determine the 100 -year peak flow generated by runoff in the contributing basin of Channel 6 at the Laura Street improvements. The calculated flowrate is used to compare to existing published FEMA and AMEC flowrates and determine an appropriate value for use in the hydraulic design of the project's culvert replacement. The flowrate is also used to verify the accuracy of the 100 -year flowrate used in the current effective FEMA HEC -RAS model. The effective model will be updated and used in the hydraulic analysis of the existing condition and design of the proposed pipe upgrades as well as the completion of a no -rise analysis for the Laura Street improvements to comply with the requirements of a floodplain development permit for the City of Springfield. Zoning The 300 -acre basin area upstream of Laura Street is roughly bounded by Woodlane Drive and V Street to the north, Debra Street to the east, R Street and CI street to the south and Laura Street to the west. The contributing area is developed predominantly with single-family residential homes (zoned R-1). There are smaller areas of denser housing (R-2 and R-3) and commercial areas (CC) in the southern portion of the contributing basin south of S street and a small area of open space / public land which cuts through the upstream basin from west to east. The Channel 6 basin area which contributes runoff at Pioneer Parkway is approximately 285 acres. There is an additional runoff contribution from just under 20 acres west of Pioneer Parkway that enters Channel 6 at Laura Street. See the Contributing Basin Exhibit in Appendix B. Soils The Natural Resources Conservation Service (NRCS) Soil survey data for Lane County indicates the hydrologic soil types in the contributing basin area are comprised of approximately 50% B soils, 40 % C soils and 10% D soils. The predominant soil types are Salem -Urban land complex and Malabon-Urban land complex. Soil data is attached in Appendix B. This distribution of soil type, along with the zoning areas determined with the City of Springfield zoning maps, was used to determine a composite curve number for the upstream areas. HP Page 3 Channel 6 Crossing at Laura Street Final Hydraulic Report Upstream Basin (Contributing Area at Pioneer Parkway) Zoning Area SF Area AC I Wei hted CN Total Basin CN R-1 Low Density) 9,925,041 227.8 77 346,360 8.0 R-2 Medium Density) 492,534 11.3 79 88 R-3 (High Density( 626,562 MA 88 78 Community Commercial 992,147 22.8 93 Open Space 337,891 7.8 68 Total Area 12,370.175 284.1 Laura Street Contributing Basin (Flows enter Channel 6 at Laura Street) Zoning Area ISF) Area (AC) Weighted CN Total Basin CN R-1(Low Density( 336,4667.7 77 R-2 (Medium Density) 346,360 8.0 79 R-3 (High Density) 18,157 0.4 88 81 Community Commercial 150,968 3.5 93 Total Area 851,971 19.6 Topography Topography is extremely flat in the entire basin. Ground slopes from east to west are typically less than 0.5°x. The highest elevation at the east end of the contributing basin is 458 and lowest is a 444 at Laura Street at the west edge. Generally, the underground storm sewer system which carries collected runoff from the furthest areas of the contributing basin progresses from east to west in increasing pipe diameter toward Pacific Park where the flow is discharged to an open channel. Flows then are conveyed in culverts beneath Shadylane Drive and Pioneer Parkway before reaching the existing pipe above Laura Street. City of Springfield GIS data was used to determine pipe diameters and slopes to calculate a time of concentration for the contributing basins. Time of concentration calculations performed for the basin area upstream of Pioneer Parkway produces a time of concentration of 193 minutes. The area contributing runoff at Laura Street produces a time of concentration of just over 40 minutes. 100 -year Peak Flow Results A Santa Barbara Urban Hydrograph (SBUH) analysis of the 284 -acre area upstream of the existing 36 -inch pipe at Laura Street (flow from Pioneer Parkway) results in a 100 -year flow rate based on the City of Springfield rainfall data (5.2 inches) of 56 cfs while the 20 -acre basin Page 4 Channel 6 Crossing at Laura Street Final Hydraulic Report contribution from Laura Street pipes at the outfall is 9.5 cfs. This flow represents runoff generated from the upstream basins and does not account for the capacity of the upstream infrastructure to convey the total flow. See Appendix B for 100 -year hydrographs. Flow Comparison The 56 cfs flowrate calculated by HHPR was compared to the effective HEC -RAS model 100 - year flow (48 cfs) and a 100 -year flow rate used in the 2014 Channel 6 Stormwater Master Plan by AMEC Environment & Infrastructure, Inc (AMEC) (61.5 cfs) to verify the accuracy of the existing data and to determine which flowrate to use in the hydraulic analysis of the Laura Street improvements. The effective FEMA HEC -RAS model has a 100 -year flowrate of 48 cfs at the downstream edge of Pioneer Parkway (Section 11473) and 52 cfs downstream of Laura Street (Section 10838). The HEC -RAS model was accepted in 2017 with LOMR 16-10-1640P-415591. The LOMR was completed for the City of Springfield by AMEC Foster Wheeler Environment & Infrastructure, Inc. (AMEC). The flows in the hydraulic model were computed based on the previous study done for the City of Springfield by AMEC in 2014 to create the Channel 6 Stormwater Master Plan. The hydrologic analysis was completed using the program SWMM. This model not only calculated runoff generated but also incorporated hydraulic routing using existing conveyance facilities, geometry data and survey information to estimate storage volumes in areas created by undersized infrastructure along Channel 6 which causes flow to back up in multiple locations. Storage and inadequate capacity of existing pipe sizes reduce peak flows reaching downstream areas. This is the reason the value of 100 -year peak flow in the effective model is lower than the runoff from the entire upstream basin. HHPR's hydrologic analysis determined a peak flow generated by the upstream basin using a time of concentration calculation that assumes the entire peak runoff rate reaches the Laura Street pipe with no barriers to flow. For this reason, the difference between the HHPR runoff -generated flow rate and the HEC -RAS routed -runoff flow rate used in the hydraulic model is reasonable. See Appendix D for a table of HEC -RAS flow rates. HP Page 5 Channel 6 Crossing at Laura Street Final Hydraulic Report The basis for the effective hydraulic model flowrates is the 2014 Channel 6 Stormwater Master Plan by AMEC. The analysis of Channel 6 and possible alternative improvements to reduce areas of flooding along the channel used a 100 -year existing flow rate of 61.5 cfs for hydraulic analysis of the existing 36 -inch pipe at Laura Street (for Improvement Alternatives A1-2 and A2- 4 at the project location). This flow rate is not a reasonable comparison to the HHPR computed runoff rate as it represents a hydrologic and hydraulic analysis of a theoretical condition where multiple improvements and upgrades as well as enhanced storage areas are created along the length of Channel 6 both upstream and downstream of the Laura Street improvements. The CIP was significantly updated for the 2017 CIP Ietterwhich is included in Appendix D. CIP 5 is being implemented with the Laura Street project except for the shape of proposed culvert. The 2017 CIP letter proposes a concrete arch section whereas the proposed design specifies a circular concrete culvert. HHPR has determined that the existing flow rates in the effective HEC -RAS model are reasonable based on the information and method used to generate them. Further, HHPR proposes to use the effective model HEC -RAS flow rates in the hydraulic analysis of the proposed Laura Street upgrades. Fish Passage Considerations Per environmental analysis and observation, Channel 6 does not support Endangered Species Act (ESA) listed fish. Conversations with the Oregon Department of Fish and Wildlife (ODFVV) who visited the location confirm that fish passage considerations are not a requirement for this project. See Appendix A for ODFW correspondence. Regulatory Standards Floodplain Development Regulations A permit from the Oregon Division of State Lands (DSL) and U.S. Army Corps of Engineers (USACE) is required due to work within a FEMA regulatory floodplain and floodway. The area of Channel 6 at Laura Street is designated a Zone AE on the Flood Insurance Rate Map (FIRM) for Lane County 41039C1 134F, effective June 2, 1999. Zone AE is subject to Page 6 Channel 6 Crossing at Laura Street Final Hydraulic Report inundation by the 1-A annual chance flood where base flood elevations have been determined. The 1 %annual chance flood (100 -year flood is also known as the base flood. The floodway is the channel of stream plus any adjacent floodplain areas that must be kept free of encroachment so that the 1% annual chance flood can be carried without substantial increases in flood heights (FEMA, 2009). The City of Springfield Floodplain Oveday District applies to all areas of special flood hazard within the Springfield urban growth boundary. Per SDC 3.3.430(8)(4) substantial improvements are required to demonstrate through hydrologic and hydraulic analysis that any proposed encroachment in the floodway will not result in any increase in flood levels within the community during the base flood occurrence. A floodplain development permit for the improvements is necessary. Design Approach Lane County and the City of Springfield wish to upsize the existing portion of 36" culvert beneath Laura Street during the upcoming roadway upgrade project. Although the timing does not follow the order of improvements recommended by the CIPS document, the culvert upgrade will avoid disturbing the upcoming roadway upgrades in the future. Design Objectives and Constraints The objective of the increase in diameter of the existing pipe under Laura Street is thatwhen future improvements upgrade the size of the remaining 36 -inch pipe that connects at Laura Street and extends 370 ft upstream toward Pioneer Parkway, the increased capacity of these two pipe lengths will reduce the backup that occurs at the upstream pipe entrance and causes a backup of flow which extends upstream through the Pioneer Parkway culverts and reduce the water surface elevation of the flooding that occurs over the pipe in the vicinity of Laura Street. Site constraints include existing overhead utility poles and underground utilities in Laura Street. Existing water, sanitary, and gas (8" high pressure and 2" standard) pipes run north/south in Laura Street at the existing 36 -inch pipe. It is assumed that all existing utilities are installed below the existing culvert and therefore will not conflict with the proposed larger diameter pipe as the design follows the same profile as existing. Page Channel 6 Crossing at Laura Street Final Hydraulic Report Design Flows The project site lieswithin a FEMA study area, therefore design flows (10 -through 500 -year; 24-hour event) were obtained from the effective FIS LOMR for FEMA panel 41039C1 134F and the effective HEC -RAS model which was created with the LOMR. Table 1 lists the published FEMA design flows upstream of the proposed pipe improvement. i we i: r emw reaR nowS Design Slope In general, the existing Channel 6 slope is approximately 0.2°x. The surveyed inverts at the 36 - inch pipe upstream of Laura Street show this 38OLF section at 0.27° slope. Existing elevations for the 46 LF of 36 -inch segment of pipe under Laura Street indicate a 0.46° slope. Because the street section will be slightly widened to the east, the existing manhole which connects these two pipe sections will be removed. Anew, larger manhole will be installed east of the proposed right-of-way, within the existing easement, to accommodate the proposed pipe size (and future connecting pipe diameter upgrade) and the length of new, larger pipe will be installed between the proposed manhole and the west side of Laura Street. The channel will be graded at 0.5% to provide positive slope downstream of the culvert outfall. The proposed pipe slope is 0.25°x. [CULVERT CL - PROFILE VIE ` m Figure 1: Channel Profile (NAVD 88) HP Page 8 100 -Year 500 -Year 10 -Year Peak 5 Year Peak Cross Section Peak Flow Peak Flow Flow (cfs) F Flow (cfs) (cfs) (cfs) 11473 45 47 48 48 i we i: r emw reaR nowS Design Slope In general, the existing Channel 6 slope is approximately 0.2°x. The surveyed inverts at the 36 - inch pipe upstream of Laura Street show this 38OLF section at 0.27° slope. Existing elevations for the 46 LF of 36 -inch segment of pipe under Laura Street indicate a 0.46° slope. Because the street section will be slightly widened to the east, the existing manhole which connects these two pipe sections will be removed. Anew, larger manhole will be installed east of the proposed right-of-way, within the existing easement, to accommodate the proposed pipe size (and future connecting pipe diameter upgrade) and the length of new, larger pipe will be installed between the proposed manhole and the west side of Laura Street. The channel will be graded at 0.5% to provide positive slope downstream of the culvert outfall. The proposed pipe slope is 0.25°x. [CULVERT CL - PROFILE VIE ` m Figure 1: Channel Profile (NAVD 88) HP Page 8 Channel 6 Crossing at Laura Street Final Hydraulic Report Channel Alignment The proposed pipe improvements will not alter the channel alignment. The upstream end is constrained by the location of the existing 36 -inch pipe which will be reconnected at the proposed manhole. The downstream alignment is constrained by the grades of the existing channel. To provide positive slope through the proposed culvert and open channel, the downstream channel will be slightly regraded. The proposed alignment is shown in Figure 2. Figure 2: Proposed Culvert Alignment Channel Shape �a aLw —.. While the proposed improvements will provide stabilization at the downstream face of the proposed culvert via headwall and the upgraded Channel 6 embankments, minor revisions are proposed to the channel shape downstream from the outfall. A 4' bottom width with approximately 60% side slopes is proposed in the regraded portion of the channel as these parameters were observed as a general average over the existing surveyed channel. Predicted Hydraulics Although the existing pipe segment under Laura Street is being upgraded to provide for future increased conveyance capacity, the connected 36 -in pipe directly upstream will remain until future improvements increase its diameter or it is removed, and the open channel segment is extended. For this reason, the proposed improvements will cause no change in the existing water surface elevations or channel hydraulics as the amount ofwater coming into the pipe from upstream will remain unchanged and proposed grading results in a 50.3 CF net cut within the Page 9 Channel 6 Crossing at Laura Street Final Hydraulic Report floodplain boundary. Refer to the Floodplain Analysis - Earthwork Exhibit in Appendix C for locations where grading will occur. The HECRAS software has limitations for modeling in-line culvert structures. Therefore, the duplicate (DEM), corrected (CEM), and proposed (RPM) models reflect the two pipe segments of pipe as one continuous culvert. For the proposed model, the culvert was upsized to 48" with the bottom 1.4 -feet "blocked" to represent an equivalent hydraulic opening as the system is inlet controlled via 36" pipe, per existing and effective conditions. The flow rate within the culvert in the restricted 48 -inch was checked against the existing 36 -inch culvert flow. The blocked depth was revised until the flow rate within the culvert in the proposed condition matched the flow rate in the existing corrected model condition. In this way, the model reflects the proposed condition in which the 48 -inch section of upgraded pipe will convey the same amount of flow as the existing 36 -inch diameter pipe until the upstream section of 36 -inch pipe is removed or replaced. No Rise The effective FEMA HEC RAS hydraulic model was used to verify existing base flood (100 -year) elevation at several cross sections adjacent to the proposed crossing. The model was copied and updated to reflect site specific data to establish a corrective effective model. Site specific information applied to the CEM geometry included Channel 6 surveyed cross sections and existing pipe inverts, which resulted in revised (slightly higher than the duplicate effective model) existing base flood elevations. The corrected model was then copied and updated to reflect proposed improvements to the crossing and proposed base flood elevations were obtained. The existing and proposed base flood elevations were compared at several unpublished up- and downstream cross sections to check for WSE changes. The results indicate that the proposed 48" culvert under Laura Street will not create a rise in the existing surface water elevations up - or downstream of the culvert. The hydraulic modeling results for the corrected existing and proposed conditions are shown in Figures 3-4 for simplicity. The HEC RAS model output data, for existing and proposed conditions, is attached for cross section H through J. The complete Channel 6 reach output file is available upon request. HP Page 10 Channel 6 Crossing at Laura Street Final Hydraulic Report RPAN fFMRRNer51a iEMA4os Seatkn l0 , FEMA FIS Rimardal !Na CNItlOtl P., Fbw CFM Base FaW RPM Base Ra IMI Elw lal ekv lx) CFM and RRA FkvaLLM Divere�.txl SIML 1 5706 : g 54 J 76 a 47 -0-029 11)4) 54 446.76 4460 -0.29 11713 A dj lune CUNert s �mcRF aPk 2108 54 416.76 N 7 -0.M 11629 54 446.75 76 7 4.28 1106 50 446.75 N 46 4.29 11570 50 446.72 76642 -030 11531 Pionxs NB CPNM 11493 50 445.91 60.5.65 4.29 11687 50 445.9S N167 -0.M 13473 - 48 695.84 64553 -031 11399 - Pionttr58 Culvert - - - 11326 48 44a.a9 6a4.21 -0.29 11286 48 444.53 144.23 430 11072 Laura Street Cthart 10660 46 441.42 441.20 -0.22 10838 n99 52 0135 441.16 -0.09 10600 52 441.05 44161 -0.D1 2.90 5I ",01 ML01 Pea 20467 52 49L00 66100 am 10231 52 440.98 410.98 0.00 ]0122 52 440.9) 140.9) OAK 10112 H 4076 52 440.9) 44a97 10.00 Figure 3: Existing and Proposed WSE Comparison Table (NAVD88) Figure 4: Existing and Proposed WSE Profile (NAVD88) HP Page 11 C�B . LOMP F7 Nnvom OR STATE a ES INMFr wwxea Plm: 11c[M YI67ea3 zRn v s �mcRF aPk THU I �ie i o La cn...a o�-... ml s w Figure 4: Existing and Proposed WSE Profile (NAVD88) HP Page 11 Channel 6 Crossing at Laura Street Final Hydraulic Report Conclusion To provide capacity for future upgrades, the proposed project will replace the existing 36 -inch culvert under Laura Street with a 48 -inch diameter reinforced concrete culvert. The no rise outcome was determined from a HEC RAS model reflecting the proposed culvert improvements. The technical data included supports the fact that the project will not increase the base flood elevations, floodway elevations, and floodway widths on Channel 6 at published cross sections in the LOMR 16-10-1640P-415591 for Lane County, Oregon and Incorporated Areas. The proposed project will also not increase the base flood elevations, floodway elevations, and floodway widths at the unpublished cross sections in the area of the proposed project. A certified no -rise document is included in Appendix C of this final document. HP Page 12 Appendix A: Hydraulic Site Investigation D� Laura Street Upgrade Hydraulic Analysis Photo Log (LNC -01) Date: October 19, 2022 Prepared By: Harper Houf Peterson Righellis Inc. 'A. CAPE ARCHITECTSOSURVEYCR9 205 SE Spokane Str i, SuiP, 3C9. Pmlhntl. OR W203 .n.503d21.1131 www.Mpcmm A%503.M.1171 0 so 100 200 SCALE: V = 100' R E V 1 5 1 0 H Harper wpb Houf Peterson .O Righellis Inc. awR CLTC9ERSYL �mea�dsmeev.4C wem,9v°� mmn9 PHOTO LOG INDEX MAP LAURA STREET UPGRADE SPRINGFIELD, OREGON INDEX LNC 01 i 2' nae MIA PRIVATE ROAD 72 7376 66 6 •r-" - - ►ram- - < y 67 68 69 • 1, ° .e\n 71 77 llw- Cr v 87 `. ss 91 90 92 � 96 96 98 94 r 97 93 SS �S9 36 3(5 .Q _ w PRIVATE ROAD Ll v15 11 ... _ � 'gni � tr � .���. ` 1 •1 i 58 52 53 54 55 S7 ._ PRIVATE DR4v 56 7 u U STREE Lima 1 16 17 18 19 1L 20 g w'If'�i�� �5_ "�•�•rS� 3 S 47N�. r f M � r �+� f I Photo 5 - 6. .9 1`4 'x t _'�' � "T� �JRb� T' \\t\S�\ M L �. r�S ' 3 �. . . � :�- 74� � ¢.2 �� qe� ���• is� 1 f{ . 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BAKI@odfw.oregon.gov> Sent: Tuesday, August 9, 2022 5:57 PM To: HINZE Donna L Subject: Re: Laura St Upgrade (KN 22348): draft BOC and Environmental SOW Yes, you do not need to address fish passage requirements at this site. Pete Get Outlook for i0S From: HINZE Donna L<Donna. L HI NZE@odot.oregon.gov> Sent: Tuesday, August 9, 2022 2:55:58 PM To: BAKI Pete " ODFW <Pete. BAKI@odfw.oregon.gov> Subject: RE: Laura St Upgrade (KN 22348): draft BOC and Environmental SOW So no fish passage correct? If so, that will save a lot of consultant contract money checking this out. Much thanks. Donna From: BAKI Pete " ODFW <Pete.BAKI @odfw.oregon.gov> Sent: Tuesday, August 9, 2022 1:06 PM To: HINZE Donna L<Donna. L HI NZE@odot.oregon.gov>; GILLETTE Allen<AIIen.GILLETTE@odot.oregon.gov> Cc: HANSON Josh "ODFW <Josh. HANSON@odfw.oregon.gov>; NORDHOLM Katherine E "ODFW <Katherine. E. NORDHO LM@odfw.oregon.gov>; ZI LLER Jeffrey S " ODFW <Jeffrey.S.ZI LLER@odfw.oregon.gov>; ROME R Jeremy D " ODFW <Jeremy. D. RO MER@odfw.oregon.gov> Subject: RE: Laura St Upgrade (KN 22348): draft BOC and Environmental SOW Donna; ODFW is making a no fish call at this location. Sorry about the delay and let me know if you have any questions, Pete Baki From: HINZE Donna L<Donna. L HI NZE@odot.oreaon.aov> Sent: Tuesday, August 9, 2022 12:02 PM To: BAKI Pete' ODFW <Pete. BAKI Caodfw.oreaon.aov>; GILLETTE Allen<AIIen.GILLETTECdodot.oreaon.aov> Cc: HANSON Josh "ODFW <)osh. HANSON@odfmoreaon.aov> Subject: RE: Laura St Upgrade (KN 22348): draft BOC and Environmental SOW Havent heard on this. Do we have any direction based on your visit, Pete? Donna Appendix B: Hydrology Analysis ILA m III Hydrologic Soil Group—Lane County Area, Oregon = (Laura St Upgrades) to R M ti nano namo seen aano 4sno 4smo ®no ®smo ®mm amm 3 3 M, Sae: 1:13,, 0 RPntal Atandem, (11"x 85')d,es. a Rs R N amo aoo em izn p Anes2110 7, pl�n rreraor Cmrrmwdrala: NG584 fbgeEa: U1M]me1W YJG539 LSM Natural Resources NFb Sol Survey 11MM22 i Conservation Serme National Cooperative Soil Survey Page 1 of4 Hydrologic Soil Group—Lane County Al Oregon (Laura St Upgrades) MAPLEGEND Area of tries. A01) Area of Interest(AOh Soils Soil Rating Polygons Q A 0 AID 0 B 0 BID oC 0 CID 0 D 0 N of rated or n of avail able Soil Rating Lines N A y AID y B �y BID y C y CID N D I N otrated or n of avail able Sat Rating Pei A AID B BID MAP INFORMATION _SD, Natural Resources Web Sol Survey 11182D22 sai Conservation Service National Cooperative Sail Survey Page 2 of 4 C The soil surveys that comprise your AOI were mapped at 1:20,000. CID Please rely on the bar scale on each map sheet for map ■ B measurements. G Not rated or not available Sourceof Map: Natural Resources Conservation Service Water Pastures Web Soil Survey URL: Streams and Canals Coordinate System: Web Mercalor(EPSG:385]) Transportation Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts Rails distance and area. A projection that preserves area, such as the 'y Interstate Highways Albers equal-area conic projection, should be used fmore accurate calculations of distance or area are required, US Routes This product is generated hour the USDA4gRCS candied data as Major Roads of the version date(s) listed below Local Roads Scil Survey Area: Lane Ccunly Area,OregoR Background Survey Area Data: Verson 20, Sep 14, 2022 . Aerial Photography Sail map units are labeled (as space allows) formap soaks 1:58000 or larger. Dates) aerial hnages were photographed: Jun 12, 2W1 un 19, M19 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. _SD, Natural Resources Web Sol Survey 11182D22 sai Conservation Service National Cooperative Sail Survey Page 2 of 4 Hydrologic Sol Group—lane County Area, Oregon Hydrologic Soil Group Laura St Upgrades Map unit symbol Map unit name Acres in ADI Percent of AOI 24 Chapman loam B 1.8 0.5% 32 Coburg -Urban land complex C 3.3 0.9% 78 Malabon-Urban land complex C 142.1 38.9% 100 Oxley gravelly at loam CID 30.8 8.0% 119 Salan-Urban land complex B 185.4 48.2% M24A Courtney gravelly silly day loam, 010 3 percent slopes D 21.8 5.8% Totals for Aroa of Interest 381.7 100.0% LSM Natural Resources Web Soil Survey 11/8/2022 2tillit Conservation Service National Cooperative Soil Survey Page 3 of4 Hydrologic Sol Group—Lane County Nes, Oregon Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate ofwater infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained orwell drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement ofwater or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method. Dominant Condition Component Percent Cutoff. None Specked Tie-break Rule: Higher Laura St Upgrades LSM Natural Resources Mb Soil Survey 11/11/2022 2111111 Conservation Serme National Cooperative Soil Survey Page 4 of4 Chapter2 Estimating Runoff Technical Release 55 Urban Hydrology for Small Watersheds Table 2-2a Runoff curve numbers for urban areas v Curve numbers for Cover description ------- hydrologic soil group Average percent Cover type and hydrologic condition inrpervion.4 allay Fhl/ydeveJeped urban areas (vegetation established) Open space (lawns, parks, golf courses, cemeteries, etc.) y: Poor condition (grass cover <6036) .......................................... Fair condition (grass cover 5096 to 7€%) .................................. Good condition (grass cover> 75%) ......................................... bnpervious areas: Paved parking lots, roofs, driveways, etc. (excluding right f-way)............................................................. Streets and roads: Paved; curbs and storm sewers (excluding rightuf-way)................................................................................ Paved; open ditches (including rightof-way).......................... Gravel (including rightuf-way)................................................. Dirt (including right -of -way) ...................................................... Western desert urban areas: Natural desert landscaping (pervious areas only) 4' ..................... Artificial desert landscaping (impervious weed barrier, desert shrub with 1- W 2 -inch sand or gravel mulch andbasin borders)...................................................................... Urban districts: Ccou nercial and business................................................................. Industrial............................................................................................. Residential districts by average lot size: R-1, R-2, & R-3 1/8 acre or less (town houses).......................................................... 1/4 acre ................................................................................................ 1/3 acre ................................................................................................ 1,12 acre ................................................................................................ 1 acre................................................................................................... 2 acres.................................................................................................. Developing urban areas Newly graded areas (pervious areas only, no vegetation) 5'_____ - Idle lands (CN's are determined using cover types similar to those in table 2-2c). Approx 50% of basin is B soils, 40% C, & 10% D. Weighted average CN used 68 79 86 89 49 39 1 61 74 80 77 86 91 94 I Average run lfcondition, and 1,=0.2S. a The average percent impervious arrve shown was used to develop the composde CN's. Other assumptions are as forbore: impervious meat me directly sm,sted to the drainage system, impervious areas have aCN of 98, and pervious areas are srnsidemd equivalent to open space in good hydrologic condition CN's for other combinations of conditions maybe sr,wuted using figure 23 or 2d. a CN's shown are equivalent to those of pasture. Composite CN's maybe computed for other combinations of open spas eover type. a Composite CN's for nahual desert brol caping should be computed using figures 23 or 2d based on the impervious area percentage (CN = 98) and the pervious area CN. The pervious area CN's are arsumed equivalent to desert shrub in poor hydrologic eoragdon. 5 Composite CN's to use for the design of temporary measures during grading and construction should be smputed using figura= 23 or 24 based on the degree ofdewlopment (impervious area pereentage) and the CN's for the newly graded pervious areas. (210 -VI -TR -66, Second M, dune 1986) 2-6 98 98 98 98 98 98 98 98 83 89 92 93 76 85 89 91 72 82 87 89 63 77 85 88 96 96 96 96 85 89 72 81 88 91 93 65 77 85 90 92 38 61 75 83 87 30 67 72 At 86 25 54 70 80 85 20 51 68 79 84 12 46 65 77 82 77 86 91 94 I Average run lfcondition, and 1,=0.2S. a The average percent impervious arrve shown was used to develop the composde CN's. Other assumptions are as forbore: impervious meat me directly sm,sted to the drainage system, impervious areas have aCN of 98, and pervious areas are srnsidemd equivalent to open space in good hydrologic condition CN's for other combinations of conditions maybe sr,wuted using figure 23 or 2d. a CN's shown are equivalent to those of pasture. Composite CN's maybe computed for other combinations of open spas eover type. a Composite CN's for nahual desert brol caping should be computed using figures 23 or 2d based on the impervious area percentage (CN = 98) and the pervious area CN. The pervious area CN's are arsumed equivalent to desert shrub in poor hydrologic eoragdon. 5 Composite CN's to use for the design of temporary measures during grading and construction should be smputed using figura= 23 or 24 based on the degree ofdewlopment (impervious area pereentage) and the CN's for the newly graded pervious areas. (210 -VI -TR -66, Second M, dune 1986) 2-6 Laura Street Upgrade Time of Concentration Break Down Prepared by Harper Houf Peterson Rlghellls Inc. -Input parameter Job No, LNC01-12 January 2023 Existing and Proposed Conditions '2 -Year, 24 -Hour Rainfall= 13 inches SS,rinr ield t<Plpe flow CPipe floe: L- 4845R L= 218R C sheet flow S- 0.18% S= 0.31 L- 215% n- 0.013 Pipe n= 0.013 Pipe CRpe I. S= 0.3% D- 4 D= 42 in L= 196.8% in = 0.011 Paomment V- 442 fps V= 5.80 fps S= 0.54% lois 4.55 Min tm= 1.83 Min fins 1163 Min in = 0.013 Pipe D= 48 In t Pipe flow RMr.. t Pipe flaw. t<Pipe flow: V= 8.37 fps L- 30ftL- R L= R fa• 0.39 Min S- 0.41 % S- % S= .31 % = 0.013 Pipe n= Pipe in .013 Pipe 4 Shallow Concentrate flow D- 12 in D= D= Min L= 118]% V- 3.00 fps V- 161 fps V= 6.34 fps S= 0.01% tip= 2.17 Min tip= 406 Min tip• 0.02 Min Cp= 16.1315 Unpai V= 0.16 fps C Pipeflow delta. Dnw. CPipe flaw. t<Pipe flaw: 1.. 12.26 Min L- WOR L- L= 154.5% S- 0.4 N, S- % S= 0.6 % CRpe flow = 0.013 Pipe n= Rpe n= 0.013 Pipe L= 80% D- 12 in D= in D= Min S= 0.88% V- 2.86 fps V- 570 fps V= 8.82 fps in = 0.013 Pipe tip= 2.33 Min I. is 1176 Min tip• 0.29 Min D= 48 in t Pipe flow V= 10.68 fps t<Rpe I. Debs. Dnw. L- 175.5R t<Pipe flow: fa• 0.12 Min L= 300% S- 022% L= 78% S= 1 % n- 0.013 Pipe S= 0.28 % CRpe flow in - 0.013 Pipe D- Q In n= 0.013 Pipe L= R D- 18 in V- 489 fps D= Min S= 0.2% V- 5.92 fps tm= M60 Min V= 5.81 fps n= .013 Pipe t. is Di Min tip• 0.22 Min D= Qin t Pipe flaw. V= 509 fps f<Pipe flow TSttarL - f<Shallow Concentrate flow: fa. 0.00 Min L= 241% 5- % L= 265.565.5 R S= 0.27% n= .ft Pipe S= 0.01 % f<9hallaw Concentrate flow PARK in = 0.013 Pipe D= ^ Cp= 16.1315 Unpi L= 1,100% D= 18 in V- am fps V= 0.16 fps S= 0.01 % V= an fps kp= 450 Min tips 27.43 Min Cp= 16.1315 Unpinned I�p• 1.32 Min V= 0.16 fps C Pipe flaw: tars 113.63 Min t<Rpe flow L= 123% L= 280% S= 0.59% CRpe I. Shady Lane Dr S= 0.24% n= 0.013 Pipe L= 116% = 0.013 Pipe tPipe flow D= Min S= 0.21 D- 24 in L- 134R V= 8,74 fps in = 0.013 Pipe V- 3.51 fps S- 0.21% fins 0.23 Min D= 42 in tip= 1.33 Min n - 0013 Pipe V= 4.77 fps D- Qin [Pipe flow: I. is 0.41 Min t<Rpe I. V- 477 fps L= F 107% L= 527% kp= 1.52 Min S= an% 4 Shallow Concentrate flow S= 0.15% in = 0.013 Pipe L= 54 % = 0.013 Pipe D= M in S= 0.01 % D= 24 in V - 5.34 fps Co= 16.1315 Unpaired V= 2.78 fps tip= 0.33 Min V- 0.16 fps lap• 3.16 Min tQ= 5.58 Min I, Sub Trial= 15.71 Min Hr Sub Total= 7.26 Min t. Sub Total= 29.16 Min t, Sub Total= 132.38 Min Laura Street Upgrade Time of Concentration Break Down Prepared by Harper Hour Peterson Rig hell ls Inc. Job No. LNW1-12 January 2023 Pioneer Northbound I Pioneer Southbound iEa 76 it Diameter is In Debate 0.1 % t Pipe flow 0.013 Pipe L- 126R Win S- 001% 2.97 fps - 0.013 Pipe 1.43 Min D- din v- 1.W fps kv- 202 Min 54.5 R 0.42% 0.013 Pipe 36 In 609 fps 0.15 Min 200 R 1% 0.210 31.26 Min 420 R 0.24% 16.1345 Unp 0.79 no. 8.86 Min Lawes Si 190 R 0.5 % 0.013 Pipe 18 In 419 fps 0.76 Min —Input paramga Intl Ran Pioneer concentrate I. R Unpaged 0.16 fps 0.30 Mn aeon of Laura great MH R379.6 R 0.28 % 0.013 Pipe 36 In 4.97 fps 1.27 Min 15.5 0.09 0.013 MM. 36 2.82 is 0.27 Total L= 7,451 R Total to• 193 min Hydrograph Report Hydrafica Hydrogwhs Falensim fa Auto es civil 3M by Autodesk, Inc. J I= Wednesday, 01 / 18 /21123 Hyd. No. 9 Upstream as a Single Basin 284 AC Hydrograph type = SBUH Runoff Peak discharge = 58.65 cfs Storm frequency = 100 yrs Time to peak = 9.47 hrs Time interval = 2 min Hyd. volume = 3,066,553 cuft Drainage area = 284.000 ac Curve number = 79 Basin Slope = 0.0% Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 193.00 min Total precip. = 5.20 in Distribution = Type IA Storm duration = 24 hrs Shape factor = n/a Q (cfs) 60.00 40.00 10.00 0.00 ' 0 4 Hyd No. 9 Upstream as a Single Basin 284 AC Hyd. No. 9 -- 100 Year 8 12 16 20 24 28 32 Q (cfs) 60.00 50.00 40.00 30.00 20.00 10.00 0.00 36 40 Time (hrs) Hydrograph Report Hydrafica Hydrogwhs Fatensim fa Auto es civil 3M by Autodesk, Inc. J I= Wednesday, 01 / 18 /21123 Hyd. No. 10 Laura Street Basin 19.5 ac Hydrograph type = SBUH Runoff Peak discharge = 9.506 cfs Storm frequency = 100 yrs Time to peak = 8.10 hrs Time interval = 2 min Hyd. volume = 223,873 cuft Drainage area = 19.500 ac Curve number = 81 Basin Slope = 0.0% Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 40.00 min Total precip. = 5.20 in Distribution = Type IA Storm duration = 24 hrs Shape factor = n/a Q (cfs) 10.00 M11 4.00 2.00 0.00 0 2 4 Hyd No. 10 6 8 Laura Street Basin 19.5 ac Hyd. No. 10 -- 100 Year Q (cfs) 10.00 . ff 4.00 2.00 I i i i i i i i —` 0.00 10 12 14 16 18 20 22 24 26 Time (hrs) Appendix C: Hydraulic Analysis 0 ENGINEERING 'NO -RISE' CERTIFICATION This is to certify that I am a duly qualified engineer licensed to practice in the state of Oregon. Is it to further certify that the attached technical data supports the fact that proposed Laura Street Upgrades will not impact the Base Flood Elevations (100 -year flood), floodway elevations, and the floodway widths on Channel 6 at published sections in the Flood Insurance Study for Lane County — Community Number ID 415591 and the City of Springfield Community Number ID 415592 LOMR 16-10-1640P effective October 17, 2017 and will not impact the Base Flood Elevations (100 -year flood), floodway elevations, and floodway widths at unpublished cross-sections in the vicinity of the proposed development. Attached are the following documents that support my findings: Channel 6 Crossing at Laura Street - Final Hydraulic Analysis Report. Printed Name: Angela Martinec. P.E. Title: Project Hydraulic Engineer Email: Angelam(dhhpr.com Address: 205 SE Spokane Street Suite 200 City: Portland State: OR Zip Code: 97202 Date: May 15. 2023 ig seal or stamp: PROFF19 �5 .GINE 75,063 �� 2Ci 7 GON U a �. 29, tiQG �QMARIEMPP EXPME5: 12/31/2024 I i LI II I I I EXISTING FACE OF BUILDING,TYP. - DITCH EXCAVATION ASSUMED = 67 CU YDS JED PAO V%� GI Nss/0'? 77,944 `�� ORF.G06 _ �gUJ.BPPMP EXPMS: 12/31/2023 DATE Imm Ohl EXISTING DRAINAGE o CHANNELWIDTH l EXISTING BOTTOM OF 1 DRAINAGECHANNEL FLOODPLAIN BOUNDARY, TYPICAL 7-1EXISTING PROPERTY LINE, TYP. I SIM `EXISTING EASEMENT, TYP. PROPOSED TCE, TYP. PROPOSED R/W, TYP. EXISTING R/W, TYP. �\ REV61ON FLOODPLAIN EARTHWORK ANALYSIS CUT (CU. YDS) NET (CU. YDS( 169.12 118.82 50.3 (CUT( APPR D LAURA STREET UPGRADE SPRINGFIELD, OREGON LANE COUNTY FLOODPLAIN ANALYSIS - EARTHWORK EXHIBIT FLOODPLAIN BOUNDARY, TYPICAL V DESIGNED: HHPP REVIEWER: RJR CHECKED: N4W DRAFTER: HHPR DATE s EET sHEFT NO. 04/1e/2023 of 1.0 Laura Street Upgrades (Springfield) No -Rise: 100 -Vex Water Surface Elevation Output from HEC RAS Prepare Ny Xaryx Xw1 Pen- RIgheen; Inc. Job No.INC-01 May 2023 Duplicate Effectipe Model (DEM) 0.Mr FEMA 0.Ner5G puplkatt MMel RNerstt iEMAfrox Moo,_ PMlle QTWI Min CS EI IRI W.S EIev IRI Ca[WS ft E.G. EIev IRI E.G. Mope IR/R) VNclnl IR/s Now Arca Iw RI Tap WM[s IRI Frouhpfsl Channels 11761 11761 1 1WYear 50 LM 96 I .0 I. .35 40653 00.00 018 LW 63)9 003 Channels iD47 11747 100Year 50 44087 1 406.53 1 4@20 40653 00.00 I OAS 055 6]07 00] Channels 11703 11703 1WYear CUNeN N/A Channels 116. 11658 1WYear 50 440.78 406.5] L0140 40653 00.00 0M 333 3W3 003 Channels 11639 11.9 1WYear 50 44069 406.5] .219 4065] 00.00 040 ]38 ll00 0. Channels ]]585 ]]585 ]W Year 50 44080 406.5] OW 40651 00.00 046 ]]0 530 OM Channels 11570 1]570 ]W Year 50 440.56 4060) 4@0) 40650 00.W ]45 30 336 011 Channels 11531 11531 100Year CulveN N/A Channels 11093 H093 ]W Year 50 44003 405.)0 4@.10 405 J3 00.W ]35 31 30.] 011 Channels 11.7 11.7 1WYear 50 44009 405.)1 OW .132 00.W 053 90 336 005 Channels 11073 11073 100Year 48 03989 I 405.58 40353 40563 0. 355 19 338 031 Channels ]]399 ]]399 ]W Year CUIveN N/A Channels 11336 11336 100Year 48 44027 44020 40]99 440.39 0W3 3. Channels 112. 112M 1WYear 48 03983 44028 401 E6 44029 0. 1. 1 48 1 538 1 013 Channels 11073 111072 1WYear CulveN N/A Channels 1. 11. 10MYear 48 4.3. 40120 440.73 40169 9 5] 067 Channels irs. 1W38 I 1WYear 53 03865 401.13 OW 40133]02�.330L14109 011 flannels ]CE07 ]OfAJ ]W Year 53 03755 401. OW .10)1Js 011Channels ].W 1.9 ]W Ytar 53 03)33 40101 OW 401.]00 016Channels 1.67 1.67 1WYear 53 03751 LOL. OW .10319.1 0Channels ].3] ].3] IWYtar 53 03550 440.98 OW 4409931.7 0W Channels ].33 ].33 IWYtar 53 036.]0 440.9) OW 4409836.7 0WChannels 10113 10113 H .Year 53 036.1] 440.97 03)55 44098316 0W Laura Street Upgrades (Springfield) No -Rise: 100 -Vex Water Surface Elevation Output from HEC RAS R arN by Haryx Hw1 Mr RlgbHba Inc. AW No. UNC01 MaY= Come, ted Effective Model (CEM) 0.Mr FEMA RiNer SM Cor-retl Monel Reser Sa FEMAQo. SeWm Pwile QTOGI lift) Min C6 El )R) W.S Ek. )R) C1i1 W.I. IN) E.G. El- )ft) E.G. Slope Wft) VeI C I n I I./i) FWWArea )oI R) Top WNih )R) Emutlep C61 Cbannel6 11761 11]61 I 10]Year 50 440% 44636 442.35 44636 1. 015 1 467 6908 001 Cbannel6 11]4] 11]4] MYear 54 440$] 446.76 442.20 44636 OCN 0.12 I 521 6103 ONu Cbannel6 11]0.3 1170.3 MYear Culvert N/A flannel. 11658 11658 MVIM r 54 gg0.]8 gg6.]6 442.84 gg6.]6 OCN 0]3 239 303.1 0@ C Mnrel6 11629 11629 MVIMr 54 ggOb9 gg635 442.19 gg636 OCN 039 162 2629 0-01 CWnml6 11586 11586 .Year 50 440s4 446.75 O.W 446.76 OCN 1 041 11 62.0 1 OW4 CWnral6 Inn I15T1 MVIM r 50 44056 446.8 442.07 44635 1 OCN I 140 I 36 I 34.5 I 0.10 CWnral6 1]531 1]531 MVIM r Culvert N/A CWnral6 11492 11492 MVIM r 50 44043 445.94 442.W 4459] I 0000129 39 60.5 0.10 CWnral6 U4s7 U4s7 MVIM r 50 44049 445.95 0.. 445ss O CO 049 102 33.6 0-05 CWnral6 11473 11473 .Year q8 83949I 48593 1 OM 1 243 1 33.7 1 029 CWnral6 113" 1U" MYear Culvert N/A CWnral6 11326 11326 MYear 48 4403] gg4.49 441." gg4b2 OAp1 2$9 17 65.1 025 CWnral6 11286 11286 MYear 48 439$2 gg4.53 441.. gg45o OCN Oso Is 943 009 CWnral6 IUX7 IUX7 MYear Culvert N/A CWnral6 1044 1044 MYear 48 43849 441.42 440.43 44153 0W3 1 2.E0 ]8 11.7 037 CWnral6 1X38 1X38 I MYear 52 439-03 44125 0.00 44142 ODs 328 16 11.5 048 CWnral6 U1E0] U1E0] MYear 52 43]55 441.0.5 0.00 441w 0= 145 36 1]3 0.17 CWnral6 10190 10190 MYear 52 43733 441.01 0.00 441M OCN 138 38 18.4 0.16 CWnral6 U1467 ll1467 MYear 52 43751 I 44LOO 0.00 oo1oa I OCN 1 137 38 I19.1 0.17 CWnral6 UY221 UY221 MYear 52 835541 W." 0.00 440." I OCN I OR3 63 1 213 1 0-08 CWnral6 111122 111122 MYear 52 436.14 1 440." 0.00 wss I OCN I 091 EO 1 26.7 111 009 CWnral6 Un. Un. H MYear 52 436.11 I W." 437.55 wss I OCN I ORS Is 1 31.6 1 0-08 Laura Street Upgrades (Springfield) No -Rise: 100 -Vex Water Surface Elevation Output from HEC RAS PrcparN by Haryx Hw1 PH RlgbHba Inc. AW No. UNC01 MaY= Revised Proposed Model (RPM) 0.Ner FEMA RiNer SM Pciposecl Mocol RiNerSn FEMAQof SeWm Pwile QTOGI lift) Min C6 El )R) W.S Ek. )R) Crit W.S. IN) E.G. El- )ft) E.G. Slope Wft) Vel r1nl Ift/s) FWw Area )ol IN Top WNih )R) Emutlep C61 Cbannel6 11761 11]61 I l0]Year 50 440% 44647 444.35 44647 1. 019 390 6u. 002 Cbannel6 11]4] 11]4] MYear 54 440$] 446.47 44220 44647 OCN 0.15 443 61]2 ONu Cbannel6 11]0.3 11713 MYear Culvert N/A flannel. 11658 11658 MVIM r 54 gg0.]8 gg6.4] g42.g4 gg6q] OCN 02] 218 2023 0@ C Mnrel6 11629 11629 MYear 54 ggOb9 gg6.4] 842.19 gg6q] OCN 0. 135 168.1 0-04 CWnml6 11586 11586 .Year 50 ggOso 446.46 O.W 4464] OCN 1 Oq6 I 112 51.3I Oos CWnneI6 115]0 115]0 MVIM r 50 440% 446.42 442.07 446.46 1 OX00 I Iq8 I 34 1 32.2 1 0.11 CWnneI6 1]531 1]531 MVIM r Culvert N/A CWnneI6 11492 11492 MVIM r 50 440,3 445.65 442.10 445,58 1 OX00 1 137 36 23.8 0.11 CWnneI6 U4s7 U4s7 MYear 50 84049 445.6] O.W 445b] OCN 054 co 32.5 OAK CWnneI6 114]3 114]3 .Year q8 83949 445.53 442.53 gg5b41 0. 1 258 19 32.6 021 CWnneI6 113" 1U" - 1MYear Culvert I N/A CWnneI6 11326 11326 MYear 48 1102] 844.20 441." 44435 OAp2 3.11 M 21.4 028 CWnneI6 11286 11286 MYear 48 83942 11423 441.65 84425 OAp1 IAK q6 46.9 0.13 CWnneI6 I1pR IUX7 MYear Culvert N/A CWnneI6 1)4A 104A MYear 48 438S7 44120 440.03 44132 I OW3 1 2.78 1 1] 9.1 036 CWnneI6 1X38 1X38 I MYear 52 13855 441.16 000 44125 0= 243 21 12.4 033 CWnneI6 UKO] UKO] MYear 52 43]55 441.04 0.00 44LY] OX00Iq6 36 1].6 0.1] CWnneI6 10190 10190 MYear 52 43733 441.01 0.00 44L4 OAIW 138 38 1 18.4 0.16 CWnneI6 U1467 ll1467 MYear 52 437SI 44LOO 0.00 ooLoa I OX00 1 137 38 I19.1 0.17 CWnneI6 UY121 UY121 MYear 52 43554 W." 0.00 110." I OX00 I OR3 63 1 212 1 0-08 CWnneI6 111122 111122 MYear 52 436.14 440." 0.00 wss I OX00 I 091 EO 1 26.7 111 005 CWnneI6 Un. Un. H MYear 52 136.11 W." 437.55 wss I OX00 I ORS 65 1 31.6 1 0-08 Laura Street Upgrades (Springfield) Compare Effective and DEM Base Flood (100 -Year Water Surface) Elevations Prepared by Harper Hour Peterson Righellis Inc. Job No. LNC -01 May 2023 Base Flood Reach FEMA Model River Ste FEMA trots Section Letter FEMA FIS River Ste Location Profile Total Flow (ck) Effective' FEMA Base Flood Elm NAVD88 (ft) DEM Base Flood Elm (ft) Effective and DEM Elevation Difference (ft) z c s 11761 1 5706 c 54 446.5 446.5 0.0 11747 54 446.5 11703 Shady Lane Culvert 11658 54 446.5 11629 54 446.5 11586 50 446.5 11570 50 446.5 11531 Pioneer NB Culvert -- -- -- 1149250 445.7 -- 11487 50 445.7 11473 48 445.6 11399 -- -- Pioneer SB Culvert — — 11326 -- -- -- 48 444.2 — 11286 48 444.3 -- — 11072Laura Street Culvert 10860 48 441.2 10838 1 1 4794 1 52 441.1 441.1 0.0 10607 52 441.0 10490 52 441.0 10467 52 441.0 10221 52 441.0 10122 52 441.0 10112 H 4078 52 441.0 441.0 0.0 I FEMA Effective FIS (6/5/2020) did not include LOMR #16-10-1640P (10/17/2017). The preliminary FIS (01/28/2022) did include the LOMR data and therefore was used for WSE comparisons Legend: DEM Duplicate Effective Model CEM Corrected Effective Model RPM Revised Proposed Model Laura Street Upgrades (Springfield) Compare DEM and CEM Base Flood (100 -Year Water Surface) Elevations Prepared by Harper Houf Peterson Righellis Inc. Job No. LNC -01 May 2023 Base Flood Reach FEMA Model River Sta FEMACross Section Letter FEMA FIS River Sta Location Profile Total Flow (cfs) DEM Base Flood Elev (ft) CEM Base Flood Elev (ft) DEM and CEM Elevation Difference (ft( w `c 11761 1 5706 w o 54 446.52 446.76 0.24 11747 -- 54 446.52 446.76 0.24 11703 Shady Lane Culvert 11658 -- 54 446.51 446.76 0.25 11629 54 446.51 446.75 0.24 11586 -- 50 446.51 446.75 0.24 11570 50 446.47 446.72 0.25 11531 -- Pioneer NB Culvert 0.00 11492 50 445.70 445.94 0.24 11487 -- 50 445.71 445.95 0.24 11473 -- - -- 48 445.58 445.84 0.26 11399 -- - Pioneer 58 Culvert - - -- - 1132648 -- 444.24 444.49 0.25 11286 -- 48 444.28 444.53 0.25 11072 Laura Street Culvert 10860 -- 48 441.24 441.42 0.18 10838 I 4794 52 441.12 441.25 0.13 10607 -- -- 52 441.04 441.05 0.01 10490 52 441.01 441.01 0.00 10467 -- -- 52 441.00 441.00 0.00 10221 52 440.98 440.98 0.00 10122 -- -- -- 52 440.97 440.97 0.00 10112 H 4078 52 440.97 440.97 0.00 Legend: DEM Duplicate Effective Model CEM Corrected Effective Model RPM Revised Proposed Model Laura Street Upgrades (Springfield) Compare CEM and RPM Base Flood (100 -Year Water Surface) Elevations Prepared by Harper Houf Peterson Righellis Inc. Job No. LNC -01 May 2023 Base Flood Reach FEMA River Sta FEMACross Section Letter FEMA FIS River Sta Location Profile Total Flow (ds) CEM Base Flood Elev (k) RPM Base Flood Elev (k) CEM and RPM Elevation Difference (k) tO `c 11761 1 5706 o 54 446.76 446.47 -0.29 11747 54 446.76 446.47 -0.29 11703 -- Shady Lane Culvert 11658 54 446.76 446.47 -0.29 11629 -- 54 446.75 446.47 -0.28 11586 50 446.75 446.46 -0.29 11570 -- 50 446.72 446.42 -0.30 11531 Pioneer NB Culvert 11492 -- 50 445.94 445.65 -0.29 11487 50 445.95 445.67 -0.28 11473 -- 48 445.84 445.53 -0.31 11399 -- - Pioneer SB Culvert - -- - 11326 -- - -- 48 444.49 444.20 -0.29 11286 48 444.53 444.23 -0.30 11072 - Laura Street Culvert 10860 48 441.42 441.20 -0.22 10838 I 4794 -- 52 441.25 441.16 -0.09 10607 52 441.05 441.04 -0.01 10490 -- -- 52 441.01 441.01 0.00 10467 52 441.00 441.00 0.00 10221 -- -- 52 440.98 440.98 0.00 10122 52 440.97 440.97 0.00 10112 H 4078 -- 52 440.97 440.97 0.00 Legend: DEM Duplicate Effective Model CEM Corrected Effective Model RPM Revised Proposed Model Laura Street Upgrades (Springfield) Compare Effective and RPM Base Flood (100 -Year Water Surface) Elevations Prepared by Harper Houf Peterson Righellis Inc. Job No. LNC -01 May 2023 Base Flood Reach FEMA River Sta FEMACross Section Letter FEMA FIS River Sta Location Profile Total Flow (cfs) Effective FEMA Elev(ft) Proposed Elev (ft) Effective and Proposed Elevation Difference (ft) tO `c 11761 1 5706 o 54 446.50 446.47 -0.03 11747 -- - -- 54 -- 446.47 -- 11703 Shady Lane Culvert -- -- 11658 54 446.47 -- 11629 54 - 446.47 - 11586 -- - -- 50 - 446.46 - 11570 50 -- 446.42 - 11531 Pioneer NB Culvert - 11492 50 - 445.65 11487 -- - -- 50 - 445.67 -- 11473 -- 48 445.53 - 11399 -- - Pioneer 58 Culvert - - - 11326 48 - 444.20 - 11286 -- - -- 48 - 444.23 -- 13072 -- Laura Street Culvert 10860 48 441.20 10838 I 4794 52 441.10 441.16 0.06 10607 -- -- -- 52 - 441.04 -- 10490 -- 52 441.01 1046752 -- -- -- 441.00 10221 52 - 440.98 -- 30122 -- -- -- 52 - 440.97 -- 10112 H 4078 -- 52 441.00 440.97 -0.03 Legend: DEM Duplicate Effective Model CEM Corrected Effective Model RPM Revised Proposed Model Laura Street Upgrades (Springfield) Compare Base Flood (100 -Year Water Surface) Elevations Prepared by Harper Had Pearson Righelis Inc. Jab N. LNC -01 May 2023 Base Flood Elevations (BFEs) (ft) Reach FEMA Model River Sts FEMA Cross Section Letter FEMA FIS River Ste Location Profile Total Flow (If.) Effective FEMA Elev(ft) DEM Elev(ft) CEM EMefft) RPM EMv(Jt) - 11761 1 5706 c 54 446.50 446.52 446.76 446.47 11747 54 446.52 446.76 446.47 11703 Shady Lane Culvert 11658 54 446.51 446.76 446.47 11629 54 446.51 446.75 446.47 11586 50 446.51 446.75 446.46 11570 50 446.47 446.72 446.42 11531 Pioneer NB Culvert 11492 50 445.70 445.94 445.65 11487 50 445.71 445.95 445.67 11473 - -- -- 48 -- 445.58 445.84 445.53 11399 - -- Pioneer SB Culvert -- -- -- -- 11326 48 444.24 444.49 444.20 11286 48 444.28 444.53 444.23 11072 Lau. Street Culvert 10860 48 441.24 441.42 441.20 10838 1 4794 52 441.10 441.12 441.25 441.16 10607 52 441.04 441.05 441.04 10490 52 441.01 441.01 441.01 10467 52 441.00 441.00 441.00 10221 52 440.98 440.98 440.98 10122 52 440.97 440.97 440.97 10112 H 4078 52 441.00 440.97 440.97 440.97 Legend: DEM Duplicate Effective Model CEM Corrected Effective Model RPM Revised Proposed Model Appendix D: Reference Documents 0.2 FLOOD INSURANCE- STUDY NSURANCESTUDY LANE COUNTY, OREGON ANDINCORPORATED AREAS VOLUME 1 OF 4 COMMUNITY COMMUNITY NAME NUMBER COBURG, CITY OF 410119 COTTAGE GROVE, CITY OF 410120 CRESWELL, CITY OF 410121 DUNES CITY, CITY OF 410262 EUGENE, CITY OF 410122 FLORENCE, CITY OF 410123 JUNCTION CITY, CITY OF 410124 LOWELL, CITY OF 410125 OAKRIDGE, CITY OF 410126 SPRINGFIELD, CITY OF 415592 VENETA,CITY OF 410128 WESTFIR, CITY OF 410289 LANE COUNTY, UNINCORPORATED AREAS 415591 REVISED: JUNE 5, 2020 o�P�A�a =Q Federal Emergency Management Agency Flood Insurance Study Number 41039CV001B Effective FIS does not contain detailed study of Channel 6. See LOMR 16-10-1640P October 17. 2017 NOTICE TO FLOOD INSURANCE STUDY USERS Communities participating in the National Flood Insurance Program have established repositories of flood hazard data for floodplain management and flood insurance purposes. This Flood Insurance Study may not contain all data available within the repository. It is advisable to contact the community repository for any additional data. The Federal Emergency Management Agency (FEMA) may revise and republish part or all of this FIS report at any time. In addition, FEMA may revise part of this FIS report by the Letter of Map Revision process, which does not involve republication or redistribution of the FIS report. Therefore, users should consult with community officials and check the Community Map Repository to obtain the most current FIS report components. This publication incorporates revisions to the original Flood Insurance Study. These revisions are presented in Section 10.0. Volume 2 of this FIS Report pertains to the Physical Map Revision for Lane County, Oregon. All elevations in Section 10.2 are in NAVD88 and the floodway data table and profile graph for the Siuslaw River have been converted to NAVD88. Initial Countywide FIS Effective Date: June 2, 1999 Revised Countywide Date: June 5, 2020 VOLUMEI Figures Figure 1: Floodway Schematic..............................................................................................80 TABLE OF CONTENTS VOLUME 1 -JUNE 5, 2020 Page 1.0 INTRODUCTION..................................................................................................1 1.1 Purpose of Study ............................................................................................1 1.2 Authority and Acimowledgements.......................................................................1 1.3 Coordination................................................................................................2 2.0 AREA STUDIED.................................................................................................... 3 2.1 Scope of Study. .............................................................................................. 3 2.2 Community Description................................................................................... 4 2.3 Principle Flood Problems.................................................................................. 8 2.4 Flood Protection Measures............................................................................... 15 3.0 ENGINEERING METHODS................................................................................... 18 3.1 Hydrologic Analysis....................................................................................... 19 3.2 Hydraulic Analyses....................................................................................... 23 4.0 FLOODPLAIN MANAGEMENT APPLICATIONS....................................................... 31 4.1 Floodplain Boundaries.................................................................................... 31 4.2 Floodways.................................................................................................. 33 5.0 INSURANCE APPLICATION.................................................................................. 81 6.0 FLOOD INSURANCE RATE MAP............................................................................ 81 7.0 OTHER STUDIES................................................................................................. 82 8.0 LOCATION OF DATA........................................................................................... 82 9.0 BIBLIOGRAPHY AND REFERENCES...................................................................... 82 10.0 REVISION DESCRIPTIONS.................................................................................... 89 10.1 First Revision............................................................................................... 90 VOLUMEI Figures Figure 1: Floodway Schematic..............................................................................................80 TABLE OF CONTENTS (Continued) Tables Table 1: Recorded Peak Flows.......................................................................................... 10-11 Table 2: Summary of Reservoir Data...................................................................................... 16 Table 3: Effect of Reservoirs on Peak Flows............................................................................. 17 Table 4: USGS Stream Gage Locations and Years of Record. ..................................................... 21-22 Table 5: Summary of Discharges....................................................................................... 24-28 Table 6: Mannings "n" Values............................................................................................. 32 Table7: Floodway Data................................................................................................. 34-79 Table 8: Community Map History ......................................................................................... 83 Table 9: Letters of Map Change............................................................................................ 91 VOLUME2 10.0 REVISION DESCRIPTIONS (Continued) 10.2 Second Revision............................................................................................ 92 Flamre8 Figure2: FIRM Panel Index.............................................................................................................................101 92 Figure3: FIRM Notes to Users.........................................................................................................................102 96 Figure4: Map Legend for FIRM......................................................................................................................105 Figure 5: Coastal Transect Schematic...............................................................................................................120 Figure 6: 1% Annual Chance Total Stillwater Elevations for Coastal Areas ...................................................122 Figure 7: Transect Location Map......................................................................................................................129 Tables Table 10: Listing of NFIP Jurisdictions.............................................................................................................. 92 Table 11: Flooding Sources Included in this FIS Revision................................................................................. 96 Table 12: Summary of Nan -Coastal Stillwater Elevations...............................................................................110 Table 13: Summary of Hydrologic and Hydraulic Analyses............................................................................112 Table 14: Roughness Coefficients....................................................................................................................116 Table 15: Summary of Coastal Analyses..........................................................................................................121 Table 16: Tide Gage Analysis Specifics...........................................................................................................123 Table 17: Coastal Transect Parameters.............................................................................................................125 Table 18: Summary of Coastal Transect Mapping Considerations...................................................................131 Table 19: Incorporated Letters of Map Change................................................................................................133 Table 20: Stream -Based VerticalDatumconversion..........................................................................................134 Table 21: Summary of Contracted Studies Included in this FIS Revision ........................................................134 Table22: Map Repositories..............................................................................................................................136 Table 23: Bibliography and References............................................................................................................137 TABLE OF CONTENTS (Continued) VOLUME Exhibits Exhibit t — Flood Profiles Amazon Creek Panels OIP-09P Amazon Creek Split Flow Panel lop Berkshire Slough Panels IIP -13P Cedar Creek Panels 14P -16P Channel A3 Panel 17P Coast Fork Willamette River Panels 18P -41P Coast Fork Willamette River Overflow Panels 42P -43P Dedrick Slough Panels 44P -45P Fall Creek Panels 46P -51P Long Tom River Panels 52P -53P Lost Creek Panels 54P -55P McKenzie River Panels 56P -117P VOLUME4 Exhibit t — Flood Profiles (Continued) McKenzie River -East Channel Panel 118P McKenzie River -North Channel Panels 119P -120P Middle Fork Willamette River (Near Springfield) Panels 121P -133P Middle Fork Willamette River (New Oakridge) Panels 134P -139P Middle Fork Willamette River Overflow Panels 140P -142P Mohawk River Panels 143P -155P North Fork Middle Fork Willamette River Panels 156P -157P Oxley Slough Panel 158P Row River Panels 159P -164P Salmon Creek Panels 165P -168P Silk Creek Panels 169P -170P Siuslaw River Panels 171P -181P Willamette River Panels 182P -194P IabaPkjH3ltxyDl64nivralaa Flood Insurance Rate Map Index Flood Insurance Rate Map Page 1 of 6 Issue Date: June 1, 2017 Effective Date: October 17, 2017 Case No.: 16.10.1640P LOMR-APP ag4Al�� T ° Federal Emergency Management Agency x Washington, D.C. 20472 GND SF LETTER OF MAP REVISION DETERMINATION DOCUMENT COMMUNITY AND REVISION INFORMATION PROJECT DESCRIPTION BASIS OF REQUEST Lane County NO PROJECT FLOODWAY Oregon HYDRAULIC ANALYSIS HYDROLOGIC ANALYSIS (Unincorporated Areas) NEW TOPOGRAPHIC DATA COMMUNITY COMMUNITY NO.: 415591 IDENTIFIER Channel LOMB APPROXIMATE LATITUDE 8 LONGITUDE: ".067,423.046 SOURCE: USGS QUADRANGLE DATUM: NAD 63 ANNOTATED MAPPING ENCLOSURES ANNOTATED STUDY ENCLOSURES TYPE: FIRM' NO.: 41039CI133F DATE: June2,1999 DATE OF EFFECTIVE FLOOD INSURANCE STUDY: Jun,02,1999 TYPE: FIRM NO.: 410391 DATE. June 2, 1999 PROFILE(S): 195P, 196P, 197P, 198P (NEW) TYPE: FIRM NO.: 41039C1141F DATE. June2,1999 FLOODWAY DATA TABLE: 7 SUMMARY OF DISCHARGES TABLE: 5 Enclosures refect charges to loading sources affectetl by this revision. ' FIRM - Flood Insurance Rate Map FLOODING SOURCE($) B REVISED REACH(El Sea Peva 2 for Additional Foodln9 address Channel 6 - From the confluence with Ib Gmlal to approtlmately 900 fast upstream of 2nd Street SUMMARY OF REVISIONS Flooding Source Effective Flootling Revised Flooding Increases Decrease. Channe16 Zone Zane AE YES YES Zone X (unshaded) Zone X (unshaded) YES YES No BFEs' BFEs YES NONE No Floodaay Floodway YES NONE ' BFEs - Base Flood Elevations DETERMINATION This document provides the determination from the Department of Homeland Security's Federal Emergency Management Agency (FEMA) regarding a request fora Letter of Map Revision (LOMR) for the area described above. Using the information submitted, "have determined that a revision to the flood harards depleted in the Flood Insurance Study (FIS) report and/or National Flood Insurance Program (NFIP) map is warranted. This document revises the effective NFIP map, as indicated in the attached documentation. Please use the enclosed annotated map panels revised by this LOMR for floodplain management purposes and for all flood insurance policies and renewals in your community. This determination is based on the food data presently available. The endosad documents provide additional information recording this determination. If you have any questions about this document, please contact the FEMA Map Informabon eXchange toll free at 1-877-336-2627 (1 -877 -FEMA MAP) or by letter addressed to the LOMC Clearinghouse, 3601 Eisenhower Avenue, Suite 500, Anaandrla, VA 22304-6426. Additional Information about the NFl P is available on our website at htlp'./M .fema.gov/nfp. Patrick'Rick" F. SacbibiL P.E., Branch Chief Engineering Services Branch Federal Insurance and Mitigation Administration 16-10-1840P 102 -I -A -C REVISED TO REFLECT LOMR EFFECTIVE: OCTOBER 17, 2017 Table 5: Summary of Discharges PEAK DISCHARGES (CFS) DRAINAGE AREA FLOODING SOURCE AND LOCATION (SO. MILES) 10 -Year 50 -Year 100 -Year 500 -Year Channel 6 Confluence with 1-5 Canal 1.4 66 76 78 90 1-5 Canal Upstream of Channel 6 Confluence 0.5 99 115 119 237 Confluence with Q -Street Canal 2.1 198 227 234 278 Q -Street Canal Upstream of Confluence with 1-5 Canal 3.8 721 830 855 1032 IREVISED DATA I -Data not available REVISED TO REFLECT LOMR EFFECTIVE: OCTOBER 17, 2017 FLOODING SOURCE FLOODWAY 1 -PERCENT -ANNUAL -CHANCE FLOOD WATER SURFACE ELEVATION SECTION MEAN WITHOUT WITH CROSS SECTION DISTANCE' WIDTH AREA VELOCITY REGULATORY FLOODWAY FLOODWAY INCREASE (FEET) (SQUARE FEET) (FEET (FEET NGVD) (FEET NGVD) (FEET NGVD) (FEET) Channel6 A 335 17 33 2.4 429.7 429.7 429.7 0.0 B 1,012 24 61 1.2 431.7 431.7 431.7 0.0 C 1,359 23 68 1.1 432.9 432.9 432.9 0.0 D 2,184 24 86 0.8 435.3 435.3 435.3 0.0 E 2,973 20 66 1.4 435.4 435.4 435.8 0,2 F 3,378 20 52 1.4 435.7 435.7 435.9 0,2 G 3,467 24 89 0.8 437.0 437.0 437.4 0,4 437.5 H 4,078 17 64 0.8 437.4 437.4 437.6 0 442.9 443.0 0.1 K 6,341 23 83 0.7 442.9 442.9 443.1 0.2 L 6,757 23 73 0.8 443.0 443.0 443.1 0.1 M 7,397 19 90 0.5 445.1 445.1 445.2 0.1 REVISED DATA ' Feel above confluence with 1-5 Canal FEDERAL EMERGENCY MANAGEMENT AGENCY > FLOODWAY DATA w LANE COUNTY, OR m AND INCORPORATED AREAS CHANNEL6 ,2 I 4,794 11 17 3.1 437.5 437.5 437.8 0.3 J 5,703 21 87 0.6 442.9 442.9 443.0 0.1 K 6,341 23 83 0.7 442.9 442.9 443.1 0.2 L 6,757 23 73 0.8 443.0 443.0 443.1 0.1 M 7,397 19 90 0.5 445.1 445.1 445.2 0.1 REVISED DATA City of — Springfield 415592 Lane Counl, Unincorporatd Areas 415591 Profile — Baseline AREA 46 Channel 6 I (EL 442) cmL9rt L ZONE ^n X0_7 AE LAURA STREET LANE DRWE II WOODLANEDRWE 47 FLOOD DISCHARGE .T CONTAINED IN STR CTURE 6 0. 44° 03' 45"SCALE p AE ZONE A� E 0.2% -ANNUAL -CHANT E o FLOOD DISCHARGE V (EL 444) ZONE AE 'e CONTAINED IN 442.9 PIONEER PARKWAY EAST S STREET STRUCTURE PACIFIC RIONEER PARKWAY WEST ,1 Ilnch-500hEt 1:6,000 w nmuon lent ,A,V,wnom TOWNSHIP 17 SOUTH, RANGE 3 WEST. 111,1 D WIIA BfEa0ep1A zm.nE, no,nx, n,nx 150 mD I'm F1;-RD eagulaturynouCway Mt City of .+ A D.zxanwNchanCe R,Da xaam, Aaa, or tx annual men a flood with areae, Springfield c y dootn l— 1:mnuneoutorwehdalnage 415592 retenfls,bRnDnsnRRaall, T..x A m FuOaa Cunalonslx Mnual In la Ghon Flood H,aN +=��•x IOTHERARFA50F ��� Moon R,du[,d Flood Rl,kdu,to L91.. 1.1) Rod Notes. m _ 44° 03' 45"SCALE 123° 01' 52" ZONE A JOINS PANEL 1142 SOUTHERN PACIFIC ,1 Ilnch-500hEt 1:6,000 NOTE: MAPAREA SHOWN ON THIS PANEL IS LOCATED WITHIN TOWNSHIP 17 SOUTH, RANGE 3 WEST. 111,1 D 150 mD I'm Mebbo a D 75 160 300 l E E NATIONAL ROW IE NZONI.F.00CERATE �zQ7 MTE MAP MAP LANE OOUUNNNOREGON w -1134„2975 C commlfl. num5m MR. a.a --UNTY 411.1 1114 Fa o SPwxGFim. C:T.aF 41,a2 1134 F 0 m c 0 REVISED TO REFLECT LOMR EFFECTIVE: OCTOBER 17, 2017 vERSlonnumnA 1.1.1.0 MP O]a39C1124F3]3AF EERV.R. NNE'1,1999 August 12, 2016 Project No. 661 M 128571 City of Springfield 255 Fifth Street Springfield, Oregon 97477 Attention: Molly Markarian amec foster wheeler Subject: Engineer Report and Narrative for Channel 6 Letter of Map Revision (LOMR) Springfield, Oregon Dear Molly: This reports the detailed hydrologic and hydraulic engineering analysis supporting the application to the Federal Emergency Management Agency (FEMA) for a letter of map revision (LOMR) to convert the update area (mostly Channel 6) Floodplain mapping to a detailed study with mapped floodway and with base flood elevations determined. The update area is shown as only an approximate study on the effective flood insurance mapping (Figure 1). Except where out -of -channel inundation occurs (about 20 percent of the total modeled length) the proposed inundation area width is narrower than the existing approximate inundation area. The change results from use of better topography based on LiDAR plus surveyed ground cross-sections and a better understanding of backwater from culverts and bridges. The update area includes Channel 6 from 5" Street downstream (west) to the 1-5 Canal, the 1-5 Canal from Harlow Road downstream (south) to the Q Street Canal, and then west (from near Fairhaven Street) to the 1-5 Freeway. The engineering analysis included modeling of flows in Channel 6 using the SWMM Version 5.1 computer program by the US Environmental Protection Agency (USEPA, 2014) and the HEC -RAS Version 4.10 computer program by the US Army Corps of Engineers (USACE, 2010). The SWMM modeling was adapted from recent drainage planning work done for the City for this watershed and was used because the small size of the watershed required detailed consideration of flow timing and attenuation. The HEC -RAS model was used for stream hydraulics because it is widely used and accepted for open channel, bridge, and culvert hydraulics. The hydraulic effects of HEC -RAS were reflected in the SWMM modeling, and the resulting flows were modeled in HEC -RAS. Flows decreased going downstream where attenuation in floodplain storage upstream of culverts was Amec Foster Wheeler Environment& Infrastructure, Inc. 7376 SW Durham Road Portland, Oregon USA 97224 Tel+1 (503) 6393400 Fax+1(503)620-7692 v .amecfw.com K:V20Wt12800\1285T1285711REPORT 160812-Channel&Lomr-RepW Docx Engineer Report: Channel 6 LOMR Springfield, Oregon significant. The models are discussed separately in the following sections, and files for both models are included with the digital submittal. Flows were contained within the channel within the update area for about 80 percent of the channel length. This is in part because the stream channels of Channel 6, 1-5 Canal, and Q Street Canal are not natural, but were enlarged and straightened as part of earlier drainage improvement projects including by the US Soil Conservation Service (SCS) in the 1960s. The flows in Channel 6 are unusually low, largely because the watershed ground surface is rather flat with pocket depressions for shallow storage of local runoff, and road crossing culverts and long runs of closed pipe along the main channels and in the lateral storm sewer have restricted flows. For example, the 100 -year discharge at the downstream end of Channel 6 is 78 cubic feet per second (cfs). While the drainage area is only 1.35 square miles (mi2), typical values for an urban area might be 200 to 300 cfs/mil. This restriction causes shallow upstream flooding (most out -of -channel inundation is less than 1 foot deep) but also reduces downstream flows. Areas of out -of -channel inundation generally extended beyond the effective, approximate inundation mapping. The locations where out -of -channel storage and flow reductions occur include the following: • Upstream (east) of Don Street, about 810 -ft length of Channel 6 is out of bank, and about 6 acres are inundated during the base flood. Almost all flooding appears confined to Guy Lee Park, where most of one home plus three park buildings are within the inundation area. Some inundation is greater than 1 -ft depth in the park plus a small area within Don Street itself. There may be potential for shallow overflow north along Don Street and Hartmann Lane or south along Nancy Avenue (Figure 2D). • Within the manufactured home park between ClearVue St and Laura St, there are two small out -of -bank inundation areas (each about 120 ft of Channel 6 length) of less than 1 -ft depth at both private road crossings of Channel 6, and 7 homes are partially within the inundation areas (Figures 2D and 2E). • Upstream (east) of Laura Street, about 510 ft of overflow occurs across the ground surface west to and across Laura Street with no channel when the 400 -ft long pipe surcharges. These surface overflows are less than 1 -ft deep except for small pockets above the pipe and a narrow depression south of the pipe from a 1 -ft pipe outlet northwest. There are 1 home plus 5 outbuildings entirely within the inundation and 3 homes and 2 outbuildings are partially or mostly within the inundation area (Figure 2E). Amec Foster Wheeler Environment & Infrastructure, Inc. Pmjeet No.: 661M 128571 August 2016 K51MMI 2800112857128571%REPORT 0160812,Channdl Lomr-Repon.D= Page Engineer Report: Channel 6 LOMR Springfield, Oregon • East of Pioneer Parkway, a series of culverts and long pipes under Pioneer Parkway (multiple crossings in series) backs flow into the broad, flat upstream area, inundating about 6 acres and 910 ft of Channel 6 length. The inundation area encompasses 3 homes entirely (two are affected by inundation more than 1 ft deep), 1 home mostly, 6 homes partly, and 2 slightly on the edge. The depth of inundation adjacent is more than 1 ft at two homes; the others are less than 1 ft. Inundation is generally less than 1 ft outside of the streets or park areas (Figure 2F). • Inlet to the T -Street long pipe, between the inlet and the recreation (bike) path west of Fifth Street inundates about 350 ft of Channel 6 length and about 1 acre of area during the base flood (1 -percent annual exceedance probability [AEP]; 100 -year event). The inundation is greater than 1 ft in some areas, and part of 1 home is within an inundation area of less than 1 -ft depth. Several homes west of the pipe inlet appear outside the 100 -year inundation area but may still be affected by shallow overflow from larger events or if the pipe inlet were blocked by debris (Figure 2F). GEOMETRY DATA Ground elevations and structure dimensions for the SWMM and HEC -RAS models were developed from a combination of the following: • LiDAR data obtained from the State of Oregon Department of Geology and Mineral Industries (DOGAMI, 2009); • Surveys of cross-section and structure elevations and locations by the City of Springfield (Springfield, 2013 and 2016); and • Field measurements and documentation of structure dimensions and inlet characteristics by Amec Foster Wheeler engineering staff conducted on May 2, 2013 (for Channel 6), September 19, 2013 (for Pioneer Parkway) and on March 25, 2016 (for the downstream Q Street and 1-5 Canals). Data were surveyed in two phases. The City first surveyed Channel 6 as part of prior drainage planning work conducted by Amec Foster Wheeler for the City. Then, for this LOMR, the City surveyed cross-sections and structures along the 1-5 and Q Street Canals. The survey data from the City of Springfield are included in the digital data submittal along with a sealed certification of the data by the licensed professional land surveyor (PLS). In addition, engineer -sealed field sketches of the stream crossing structures are included in the digital data submittal as part of the MT -2 forms. Amec Foster Wheeler Environment 8lnfrasWcture, Inc. August 2016 Project No.: 661M 128571 Page3 K:\120Wt12800\1285711285711nnRT 180812Channel&Lomr- W.Dom Engineer Report: Channel 6 LOMR Springfield, Oregon HYDROLOGIC ANALYSIS The update area includes five subwatersheds, and flows were developed specific to each subwatershed as shown in Figure 3 and as follows: • Channel 6 upstream of the 1-5 Canal (1.35 square miles; mil); 1-5 Canal upstream of the Channel 6 confluence (0.50 mi2); 1-5 Canal at the Highway 126 culvert and confluence with Q Street Canal (2.07 mi2); Q Street Canal upstream of the confluence with the 1-5 Canal (3.77 mi2); and • Q Street Canal at the 1-5 culvert and downstream end of update area (6.09 m12). Four FEMA flows were developed: 10 -percent annual exceedance probability [AEP] or "10 -year"; 2 - percent AEP ("50 -year'); 1 -percent AEP ("100 -year"); and 0.2 -percent AEP ("500 -year"). The floodway profile maintained the same flows as the 1 -percent AEP. This is consistent with standard and accepted practice for FEMA floodway analyses. However, the inundation areas upstream, even if they are often shallow (less than 1 -ft deep), reduce downstream flows, so reducing the volume of water stored may cause downstream flows and water surface elevations to increase. This effect may be partly or fully offset by providing storage elsewhere for flood water or by enlarging areas of restricted conveyance. Table 1 lists the peak flows used in the HEC -RAS model for the five profiles. The cross-section locations refer to model inputs and, in general, represent feet upstream of the start of that profile (e.g. the "main" profile along Q Street Canal, 1-5 Canal, and Channel 6; the 1-5 Canal profile upstream of Channel 6, and the tributary in Guy Lee Park). Flows for Channel 6 Modeled using SWMM Channel 6 flows were developed using the SWMM model. SWMM was used because the model already had been developed by Amec Foster W heeler during prior watershed planning work. Model geometry data were surveyed by the City or were measured during the Amec Foster Wheeler field visits on May 2, 2013 and (for Pioneer Parkway) September 19, 2013. The Channel 6 flows involved a detailed delineation of the Channel 6 watershed, and hydrodynamic analysis of rainfall -runoff and conveyance -attenuation where every pipe greater than 12 -inch diameter was modeled. The network as modeled in SWMM is shown in Figure 4. The SWMM model was adjusted for the LOMR work by incorporating culvert entrance and exit losses to better reflect hydraulics as modeled in HEC -RAS, and by adjusting some Manning n -values to Amec Foster Wheeler Environment $ Infrastructure, Inc. Pmjecl No.: 661M 128571 August 2016 K51MMI 2800112857128571%REPORT 0160812Channdl Lomr-Rapon.Daa, Page Engineer Report: Channel 6 LOMR Springfield, Oregon Table 1. HEC -RAS Flows Location & XS 100 -Yr Flow FW by Profile (cfs) 10 -Yr 50 -Yr 500 -Yr SWMM ID O St & 15 Canals: Above Channel 6 200729 1 119 119 99 115 145 SWFMP Guy Lee Park: Park Trib 100596 30 30 20 28 38 311 Channel6 13710 47 47 45 47 49 146 13441 47 47 45 47 47&2 (hand) 13023 47 47 45 47 49 xs 13710 12900 56 56 50 55 63 498 12159 54 54 49 53 59 294 11586 50 50 46 49 50 301 11473 48 48 45 47 48 101 10838 52 52 49 51 54 217 10042 55 55 51 54 61 306 9511 73 73 61 70 84 522 9017 93 93 74 89 111 310 8367 70 70 61 68 79 496 7056 74 74 63 72 84 313 6782 78 78 66 76 90 318 0 St & 15 Canals: Below Channel 6 5977 199 199 166 192 237 SWFMP 4881 234 234 198 227 278 SWFMP 3142 855 855 721 830 1032 SWFMP 2089 888 888 749 862 1073 SWFMP Notes: 1. XS is cross-section name in HEC -RAS; usually distance in ft upstream along the profile. 2. FW is Flcodway and is the same flow as the 100 -Yr; this reflects provision of comparable floodplain storage and no increase in flows from encroachment of out -of -channel storage volume. 3. SWMM ID is the Link ID in SWMM. 4. Flow in T Street pipe (XS 13441) is hand -balanced between plan P03 and P02 in HEC -RAS to account for split between overland flow (multiple cross-sections) and the long pipe. 5. 'SWFMP": Non -Channel -6 flows are from City of Springfield 2008 Stormwater Facilities Master Plan hydrologic analysis; they don't have a SWMM ID and were developed using MIKE URBAN. 6. "(hand)" denotes that the 500 -year flow in the TStreet culvert long pipe was hand -balanced between pipe. and overflow profiles at the inlet to the long pipe (cross-section 13441):2 cfs overflow 147 cis pipe Amec Foster Wheeler Environment & Infrastructure, Inc. Project No.: 661M 128571 August 2016 K:%IM l2800112857128571%REPORT 0160812-Channel&Lomr-R n.D= Page of 1 'I +,. PRIVATE ROAD r NOTE -9FE ELEVATIONS SHOWN ME WITHIN 05 FT. 0.2%AEP CONTAINED IN PRASAD CT T 1 0.2% AEP CONTAINED IN CULVERT r7 if PRIVATE ROAD . CITY OF SPRINGFIELD Amec Foster Wheeler Environment & Infrastructure, Inc. 7376 S.W. Durham Road Portland, OR 97224 ame• foster wheeler LEGEND: BASE FLOOD ELEVATION (NAVD88) FLOODWAY — CROSS-SECTION 100 -YEAR FLOODPLAIN — CHANNELCENTERLINE 500 -YEAR FLOODPLAIN — INEFFECTIVE FLOWAREAS APPROXIMATE FLOOD EXTENT LOMR UPDATE BOUNDARY Q EFFECTIVE FIRM ZONE A 0 ]5 150 Feet AE UST Ci I/P � o a o p v 1 FW - AE T ST n F,I ci P Fr 4 SHADY LP 0 r` CHANNEL 6 FIRM UPDATE FIGURE 2E - REVISED FLOOD EXTENT JULY 20,8 n0. MIM -12891 2E 1-5 CANAL UPSTREAM" OF CHANNEL - - r�..,Tw.Yar 6_��r5�r�.t -. unel 1-5 CANAL AT HWY 126 LEGEND: — Stream Centerline Watershed: L _ 1-5 Canal - Confluence with Channel 6 L _ Channels r _j 1-5 Canal -Confluence with Q -Street Canal r] Q -Street Canal - Confluence with I-5 Canal Q Q -Street Canal at 1-5 Street Canal r -7 QSTREET CA NAL AT I-5 QSTREET CANAL- UPSTREAt11 OF 1-5 CANAL — n.M IF , - •� Sources: Esn, HERE, DeLorme, Toml Intommull increment P Corp., GEBCO, USGS FAO NPS, NRCAN, GeoBas S - 0 1000 2,000 Comm. ION, nI Survey, _ Esn Japan, MEaTi Esri China (Hong Kong), swisstopo, Mapmylntlia, ®Open$treetMap contributors, end Me GIS .or Community_ Feet LATE JULY CITY OF SPRINGFIELD . CHANNEL 6 FIRM UPDATE 2016 $ePLE r=z,oss Amec Foster Wheeler amecV PROJECT NO, Environment & Infrastructure, Inc. foster FIGURE 3 - SUB -WATERSHED DELINEATION MIM 12OUl 3 ]3]6 S.W. Durham Road wheeler FIGURE Portland, OR 97224 January 20, 2017 a m e C Project No. 6-61 M-128571 foster wheeler City of Springfield 255 Fifth Street Springfield, Oregon 97477 Attention: Molly Markarian Subject: Recommended Channel 6 Capital Improvement Projects Springfield, Oregon Dear Molly: Recommendations are provided to the City of Springfield (the City) for capital improvement projects (CIPS) that would most effectively reduce flooding extent and the potential for flood damage along Channel 6. The goal of this task was to identify CIPS that could reduce the extent of flooding such that most of the flooding that is expected to occur during a 100 -year flood event would be contained within the streets or park areas. Figure 1 (panels A through F) shows the location of the suggested CIPS and the expected change (almost always reduction) in 100 -year flood extent for the with -CIPS condition relative to the existing condition as it was submitted for the Letter of Map Revision (LOMB). It is unlikely that any significant changes to the mapped existing conditions will occur as a result of FEMA's review of the LOMR submittal, but minor changes are a possibility. BACKGROUND In August 2014, Amec Foster Wheeler Environment & Infrastructure, Inc. (Ames Foster Wheeler) finalized the Channel 6 Stonnwater Master Plan (SW MP) for the City of Springfield. (Amec Foster Wheeler, 2014) The purpose of the study was to evaluate the flooding risks in the drainage basins associated with Channel 6 and to develop recommended capital improvement projects (CIPS) that could reduce flooding, improve water quality, and enhance wildlife and aquatic habitat. The flooding reduction goal, as described by the City, was to have minimal street flooding during the 10 -year storm event and to have no structures flooded during the 100 -year storm event. The majority of the hydrologic and hydraulic modeling utilized to evaluate the Channel 6 basin was performed with the U.S. Environmental Protection Agency's (EPA's) Stormwater Management Model (SWMM) Version 5 software along with data available and provided by the City. The modeling effort with the SWMM model provided projections of flow and water surface elevations (WSEs) throughout Amec Foster Wheeler Environment & Infrastructure, Inc. 7376 SW Durham Road Portland, Oregon USA 97224 Tel+1 (503)639-3400 Fax+1 (503)620-7892 .Zmecl .conn K11x 129 IM1 12BSMIv Le Ghannds-CIv LeW Rn9.W Channel Recommended Capital Improvement Projects Springfield, Oregon the basin. Based on the extent of flooding observed, the existing conditions model was altered to identify potential, and economically feasible, infrastructure changes that could meet the aforementioned project goals. Based on collaboration and input from the City, a total of five to nine CIPS were suggested (depending on the feasibility of increasing conveyance beneath Pioneer Parkway) to reduce the effects of flooding. Additional water quality CIPS were also recommended to meet the City's goals of improving water quality and enhancing wildlife and aquatic habitat, but these would not sign'rficantly affect the extent of flooding. In January of 2016, the City of Springfield published a scope of work pertaining to an update of the Channel 6 Flood Insurance Rate Map (FIRM). The current Flood Insurance Study (FIS) for Lane County (including the City of Springfield) became effective in June 1999. At that time, the detailed study included backwater flooding effects from the Willamette River up the Q -Street Canal to the I-5 crossing. The floodplain east of I-5 including Q -Street Canal, the I-5 Canal, and Channel 6 was mapped as an approximate Zone A. The mapped Zone A for Channel 6 extended from the mouth of the channel (at the confluence with the I-5 Canal) to approximately 101h Street. As described in the Scope of Work (SOW), the City of Springfield desired the preparation of a Letter of Map Revision (LOMB) application with updated mapping, including base flood elevations (BFEs). The purpose of the project was to meet the Federal Emergency Management Agency's (FEMA) community mapping requirements and to help the City more accurately determine the CIPS that would best serve its constituents. In August 2016, Amec Foster Wheeler completed the modeling efforts necessary for the City's application for a LOMR to FEMA for the mapped floodplain along Channel 6. The updated area included Channel 6 from 5' Street downstream (west) to the 1-5 Canal, the 1-5 Canal from Harlow Road downstream (south) to the Q Street Canal, and the Q Street Canal from near Fairhaven Street (west) to the 1-5 Freeway. The existing Zone -A floodplain has a break at 5th Street where flow is contained within the culvert (storm sewer system) and this location provided a natural boundary for the LOMB update, particularly considering that drainage areas less than 1 square mile are to be mapped as Shaded -Zone -X (i.e. 500 -year) for flood insurance purposes. The effective Zone A (and SOW) extended upstream of the limits of this LOMR from 5th Street to 10"' Street; however, the upstream floodplain included potential influence from Q Street Canal that could not be assessed as part of the LOMR analysis. Surcharging from piped stormwater networks can cause flooding; however, the localized flooding is not typically shown on FEMA flood insurance maps. With the exception of a bioswale / stormwater retention depression located adjacent to T Street, between 8th and 10th Streets, the entire Channel 6 stormwater conveyance system upstream of 5th Street is piped and flooding represents manhole surcharging (typically shallow) not overland flow paths. Because of the nature of this stormwater system, the upstream extent of the Channel 6 floodplain is located at the end of the open ditch at the west side of 5" Street. Amec Foster Wheeler Environment & Infrastructure, Inc. Project No.: 661 M-128571 Janwry 2017 K:\120WI2MI2&6TIM71\CIPLa 6Channal6 CIPLefler Final.Doox Page2 Channel Recommended Capital Improvement Projects Springfield, Oregon For the LOMB, flows were modeled in Channel 6 using the SWMM Version 5.1 computer program by the US Environmental Protection Agency (USEPA, 2014) in tandem with the HEC -RAS Version 4.10 computer program by the US Army Corps of Engineers (USAGE, 2010). The SWMM model used for the LOMB was based on the same model used for the SWMP in 2014. The SWMP initially utilized SWMM modeling because the small size of the watershed and large influence of the pipe network on the channel's flow required detailed consideration of flow timing and attenuation. In order to meet FEMA's standards for the LOMB, the HEC -RAS model was developed for stream hydraulics because that software is widely used and accepted by FEMA for open channel, bridge, and culvert hydraulics. The HEC -RAS model also served to validate the SWMM hydraulics. Modeling efforts completed for the LOMB indicated that the 100 -year floodplain would extend beyond the banks of Channel 6 at multiple locations and would flood numerous residences. Surface flooding was present at Don Street, Guy Lee Park, the two driveway crossings within Monta Loma Park (manufactured homes) between ClearVue Street and Laura Street, Laura Street and upstream to Pioneer Parkway, significant flooding near Shadylane Drive, and finally between T Street and the recreational bike path west of 5" Street Details regarding the modeling methodology and work completed for the LOMB application can be found in the Engineering Report and Narrative for the Channel 6 LOMB. (Amec Foster Wheeler, 2016). CAPITAL IMPROVEMENT PROJECTS ANALYSIS APPROACH The recommended CIPS were modeled in the HEC -RAS model created for the LOMB in order to evaluate the effect that proposed CIPS would have on the effective flood extent (following acceptance of the LOMB application by FEMA) and so future Conditional Letters of Map Revisions (CLOMRs) would be more readily accepted by FEMA. Initially the analysis of the CIP recommendations were based off the previous work completed as part of the 2014 SWMP. Recommended CIPS from the SWMP were evaluated using the LOMR model to determine if they were still appropriate. The CIPS from the SWMP Alternative A2 were initially evaluated, as these provided the most comprehensive flood reduction. However, this analysis showed discrepancies in the effect of the previously recommended CIPS between the SWMP and LOMR models, particularly above Pioneer Parkway. Examination of the differences between the two models found that the LOMR model, in conjunction with inputs from the SWMP model, most accurately represented the hydraulics and flooding in this area. Furthermore, the City provided input early in this project that a main CIP that would have enlarged the storm sewer under Pioneer Parkway was not feasible. Changes to that CIP would cascade effects to all downstream CIPS. It was decided based on these considerations to use Amec Foster Wheeler Environment & Infrastructure, Inc. January 2017 Project No.: 6-61 M-128571 Papa3 K:I1 I23¢p\12&57\12&571\CIPLfle6ChanneI6 CIP4Mr-Final.Docx Channel Recommended Capital Improvement Projects Springfield, Oregon the LOMR model to evaluate CIPS at similar locations using the CIP project sizes as the starting point for pipe types and sizes. An iterative process was followed to identify CIPS. Modification of the modeled stormwater conveyance system began at the upstream end (above Pioneer Parkway) to reduce the significant flooding present near Shadylane Drive and to quantify the increase in flows downstream resulting from the loss of floodwater storage (from the lowered water surface elevation). The Pioneer Parkway evaluation was special in that less invasive measures were employed instead of enlarging the pipes. Following modifications at Pioneer Parkway, the conveyance system was adjusted incrementally in a downstream progression so that CIPS were sized to accommodate flows that would result from upstream CIPS. The goal was to select CIPS that are technically feasible, buildable, and could address the City's planning objectives of preventing flooding of residential structures during the 100 - year storm event within the Channel 6 Basin, as stated during the creation of the 2014 SW MP. The seven recommended CIPS have similarities to the CIPS recommended in the SWMP, but were all updated based on the LOMR model. Although the analysis progressed from up- to downstream, CIP construction should go from downstream to upstream to ensure that downstream flooding is not worsened from construction of an upstream CIP. The conveyance capacity of the culverts beneath the two driveway crossings within the manufactured home park between ClearVue Street and Laura Street (Monta Loma Park) were also increased as a part of this modeling effort to include the increased flow for downstream CIPS. These culverts are part of the City's stormwater system, so the City may have easements over these culverts. However if that is not the case, and given that these driveways are privately owned and not part of the City's transportation system, these culverts might not be upsized in the foreseeable future. Figure 1 shows that under current conditions (LOMB model) both of the Channel 6 crossings within the Monta Loma Park would be inundated during a 100 -year storm event (shown by the green shaded area at these locations). The area shaded in green shows the reduction in flood extent from the current conditions to conditions if all seven CIPS were constructed. While not shown on the figure, if all of the CIPS were constructed with exception of the two within the Monta Loma Park, the extent of flooding would be greater than the green area shown at each of these crossings and several homes would be at risk of flooding during the 100 -year design storm. The implementation of the seven recommended CIPS would result in a reduction in the flood extent of Channel 6 as far upstream as T Street. While flooding exists at the open channel section of Channel 6 immediately west of 5" Street, no changes were proposed for the piped conveyance system between Second Street and the recreation (bike) path west of Fifth Street. Additionally, no homes would be Amec Foster Wheeler Environment & Infrastructure, Inc. Project No.: 661 M -12E571 Janwry 2017 K:\120WI2MI2&6TIM71\CIPLe 6Channel6 CIPLetter Final.Doox Paged Channel Recommended Capital Improvement Projects Springfield, Oregon flooded during the 100 -year storm event in this area. Changes to the conveyance system at this location are impractical due to the length of pipe, location of houses and lack of access to the existing pipe, and the high potential cost. The SW MM and HEC -RAS models show an increase in total flow at the mouth of Channel 6 'rf the CIPS are all implemented. However, the increase in water surface elevation is small and the relative increase in flow is small compared to the capacity of these man-made channels. Flow would still be contained within the channels and would not result in flooding issues within the downstream I-5 Canal or Q -Street Canal. Those canals were enlarged and straightened as part of earlier drainage improvement projects including by the US Soil Conservation Service (SCS) in the 1960s. CIP PROJECT DESCRIPTIONS Seven CIPS are recommended along Channel 6 (Table 1). CIPS are listed in downstream -to -upstream order as they would also be constructed in that order. Figure 1 compares the flood extents assuming all CIPS are implemented to existing conditions (as submitted with the LOMB application). The changes in water surface elevations are profiled in Figure 2. Qualitative cost estimates were compiled for this project, based on the professional judgement and experience of the authors. Table 1 - Capital Improvement Project Summary CIP I Capital Improvement IExisting Conditions Pipe No. Project Location length Proposed Capital Improvement Project 1 Culvert under Beverly Street Elliptical CMP -32 inches x]2 inches (2.6]feet x6feet; n�.026) 46 feet Upsize: Elliptical Concrete -43 inches x68 inches (3.56 feet x 5.67 feet; n=0.013) 2 Culvert under Don Street Elliptical CMP— 31 inches x 67 inches 66 feet Upslze: Ell! ptical Concrete -48 in 76 in (2.58 feet x 5.58 feet; n=0.0215)(4.0 feet x 6.33 feet; n=0.013( Private culvert under Moria Loma Park 2 CMP Circular -30 inches Upsize: Ell!ptical Concrete -43 in x 68 in 3 Crossing No 2 (2.5 feet; n=0.026) 41 feet (3.58 feet x 5.67 feet; n=0.013) 4 Private culvert under 2CMP Circular -36 inches 51 feet Upsize: Ell! ptical Concrete -48 in 76 in Monts Loma Park Crossing No 1(upstream) (3.0 feet; n=0.026) (4.0 feet x 6.33 feet; n=0.013( 5 Culvertunder Laura Street Concrete Circular -36 inches (3 feet for 46 feet; n�.013) 46 feet Upsize: Concrete Arch-36ln x 58.5 in (3.0 feet x 4.875 feet; n=0.013) Amec Foster Wheeler Environment & Infrastructure, Inc. January 2017 Pmlect No.: 6-61 M-128571 Papa5 K:I1 128BD\12557\125571\CIPLexer,Channa16 CIPLaxer-Final.Docx Channel Recommended Capital Improvement Projects Springfield, Oregon Not": CMP — Corrugated Metal Pipe CIP 1: The culvert under Beverly Street would be upsized. There was no out -of -channel flooding at this location in the LOMB model, but the increase in flow due to proposed upstream CIPS would increase flood risk at this location if this culvert were not upsized first. The recommended culvert would be able to completely convey the increased with-CIP flows and prevent the overtopping of the roadway. Even if CIP 1 were implemented, there would be a small amount of increased inundation area immediately east of Beverly Street due to the increased flow from upstream as a result of other CIPS. This increased inundation compared to the LOMB model would be shallow in depth and would not affect any residential structures. CIP 2: The culvert at Don Street would be enlarged and flooding would be eliminated at this location. The majority of flooding in the LOMR model was contained within the street and there were one home and three park buildings located within the inundation area east of Don Street. Enlarging the Don Street culvert would eliminate flooding of the home and of a significant portion of Guy Lee Park, including at least one of the park buildings. CIPs 3 and 4 are at private driveways within the Monta Loma Park. These are included because upsizing these pipes would be needed to offset increased flooding expected'rf the upstream CIPS were implemented without upsizing these culverts. These culverts are part of the City's stormwater system, so the City may have easements over these culverts. CIP 5: The culvert under Laura Street just downstream of CIPS 6 and 7 would be enlarged. This would improve conveyance in the proposed open -channel (CIP 6) and contribute to the improvements east of Pioneer Parkway (by reducing tailwater at the Pioneer Parkway culvert outlet). Modification of this culvert may require collaboration with Lane County, as there is a parcel of unincorporated land adjacent to Laura Street at this location. CIP 6: Stormwater currently discharges from the pipe beneath the southbound lane of Pioneer Parkway into a short open -channel reach before it is conveyed through a 379 -foot concrete pipe to the Amec Foster Wheeler Environment & Infrastructure, Inc. Project No.: 661 M -12E571 January 2017 K:\10XKs1 =1M& 1M71\CIPLetle0,Channel6 CIPLetter Final.Docx Page6 Pipe between Laura Concrete Circular inches Daylight piped section to Laura Street 6 Street and Pioneer (3 feet for 379 feet; n=0.013( 379 feet (match open channel near Pioneer Parkway; Parkway n=oDal Add concrete circular in existing open Open Channel channel between bus lanes -42 inches Open cennerPioner (20 feet; n�.04) (3.5 feet, n=0.013) (existing culverts under ] and Pioneer inches 55 feet roadways not changed)plusreplaceorslip- Parkway Parkway bus lanes bus 5feeCMP t for 35fe42 (3.5 feet for 35 feet; n�.024) line short section (24 -feet) of CMP under southbound bus lane and pedestrian pathway Not": CMP — Corrugated Metal Pipe CIP 1: The culvert under Beverly Street would be upsized. There was no out -of -channel flooding at this location in the LOMB model, but the increase in flow due to proposed upstream CIPS would increase flood risk at this location if this culvert were not upsized first. The recommended culvert would be able to completely convey the increased with-CIP flows and prevent the overtopping of the roadway. Even if CIP 1 were implemented, there would be a small amount of increased inundation area immediately east of Beverly Street due to the increased flow from upstream as a result of other CIPS. This increased inundation compared to the LOMB model would be shallow in depth and would not affect any residential structures. CIP 2: The culvert at Don Street would be enlarged and flooding would be eliminated at this location. The majority of flooding in the LOMR model was contained within the street and there were one home and three park buildings located within the inundation area east of Don Street. Enlarging the Don Street culvert would eliminate flooding of the home and of a significant portion of Guy Lee Park, including at least one of the park buildings. CIPs 3 and 4 are at private driveways within the Monta Loma Park. These are included because upsizing these pipes would be needed to offset increased flooding expected'rf the upstream CIPS were implemented without upsizing these culverts. These culverts are part of the City's stormwater system, so the City may have easements over these culverts. CIP 5: The culvert under Laura Street just downstream of CIPS 6 and 7 would be enlarged. This would improve conveyance in the proposed open -channel (CIP 6) and contribute to the improvements east of Pioneer Parkway (by reducing tailwater at the Pioneer Parkway culvert outlet). Modification of this culvert may require collaboration with Lane County, as there is a parcel of unincorporated land adjacent to Laura Street at this location. CIP 6: Stormwater currently discharges from the pipe beneath the southbound lane of Pioneer Parkway into a short open -channel reach before it is conveyed through a 379 -foot concrete pipe to the Amec Foster Wheeler Environment & Infrastructure, Inc. Project No.: 661 M -12E571 January 2017 K:\10XKs1 =1M& 1M71\CIPLetle0,Channel6 CIPLetter Final.Docx Page6 Channel Recommended Capital Improvement Projects Springfield, Oregon culvert beneath Laura Street. The sudden expansion and contraction within this small section of open channel reduces the conveyance of water passing through the lengths of pipe beneath Pioneer Parkway. CIP 6 would include daylighting Channel 6 between Pioneer Parkway and Laura Street and creating an open channel similar in size to the existing channel at the eastern end of the current pipe. The open channel may provide additional benefits such as improved water quality slightly or wildlife habitat. The open channel would reduce the energy losses experienced at the entrance to the concrete pipe currently and would increase floodwater storage and attenuation. Daylighting the pipe between Pioneer Parkway and Laura Street would require cooperation between the City and County as ownership of the pipe is unknown. Also, some private structures appear to overlie the pipe alignment and would need to be removed. Both incorporated and unincorporated land would be affected. The existence of an easement for the daylighted alignment is unknown. While stormwater pipes can require maintenance and clearing of sediment and debris buildup, open channels often require additional maintenance. Similar to landscaping maintenance conducted by the City along other daylighted portions of Channel 6, ongoing maintenance costs would be accrued as a result of required regular mowing and possible noxious vegetation removal activities. While reduced, flooding is still expected to occur upstream of Laura Street. Three buildings would remain entirely within the inundation area and one home and six outbuildings would be partially or mostly within the CIP inundation area. However, some of these buildings within the inundation area would have been removed as part of the daylighting project. Based on the work required and conditions present, CIP 6 would likely be the most expensive project recommended. Nevertheless, this project is feasible and is an important element of flood reduction upstream of Pioneer Parkway. CIPs 7: CIP 7 is designed to increase conveyance of stormwater beneath Pioneer Parkway in order to address the extensive flooding east of that roadway. To avoid potentially complex issues, such as the desire to not impede traffic on this major arterial, the existing pipes under Pioneer Parkway are not changed. Instead, a 24 -foot length of CMP under the southbound bus lane and adjacent pedestrian pathway would be slip -lined to reduce friction. Data provided by the City shows that only the first 24 feet of this piped portion of Channel 6 is CMP, which produces excessive friction and conveyance reduction compared to concrete pipes. Additionally, the short open -channel reach between the north - and south -bound lanes would be piped to eliminate the entrance and exit losses. (It is not known if this short open -channel reach served any environmental requirement for the Bus Rapid Transit project construction.) Finally, the inlet into the pipe under the north -bound lanes would be improved to reduce inlet losses. Overall, these effects would reduce the upstream flood elevation over 1 foot, and the resulting flood extent appears mostly contained within the roadway fight -of -way. Amec Foster Wheeler Environment & Infrastructure, Inc. January 2017 Project No.: 6-61M-128571 Papal K:I1 I29¢D\12&57\12&571\CIPLfle6ChenneI6 CIP4Mr-Final.Docx Channel Recommended Capital Improvement Projects Springfield, Oregon It appears that only one structure remains within the new limits of inundation east of Pioneer Parkway, but its depth of flooding appears less than one foot, so the structure itself may have become unaffected. The edges of many properties may still experience shallow flooding, but homes and private structures would be spared the effects of flooding for the 100 -year event. CONCLUSIONS The implementation of these recommended seven CIPS can greatly reduce the effects of flooding along Channel 6. The most severe flooding that would still exist following implementation of the proposed CIPS would be between Laura Street and Pioneer Parkway. Further flood reduction improvement in that location would be constrained by topography, channel geometry, and ownership of private property and structures close to the potential conveyance improvement areas. The recommended sequence for construction of these CIPs should be downstream to upstream without regard to whether upstream projects may provide more cost -benefit. This ensures that downstream flooding effects are not increased by construction of an upstream CIP before a downstream CIP. Amec Foster Wheeler Environment & Infrastructure, Inc. Project No.: 661 M -1 2E571 Janwry 2017 K:\120WI2MI2&6TIM71\CIPLe 6Channel6 CIPLetter Final.Docx Page8 Channel Recommended Capital Improvement Projects Springfield, Oregon LIMITATIONS This report was prepared exclusively for the City of Springfield (the City) by Amec Foster Wheeler Environment & Infrastructure, Inc. (Amec Foster Wheeler). The quality of information, conclusions, and estimates contained herein is consistent with the level of effort involved in Amec Foster Wheeler services and based on: i) information available at the time of preparation, ii) data supplied by outside sources, and iii) the assumptions, conditions, and qualifications set forth in this report. This letter is intended to be used by the City for Channel 6 capital improvement projects planning only, subject to the terms and conditions of its contract with Amec Foster Wheeler. Any other use of, or reliance on, this report by any third party is at that party's sole risk. Sincerely, Amec Foster Wheeler Environment & Infrastructure, Inc. Seth Jelen, PE, CFM, CWRE Principal Engineer— Water Resources Reviewed by: Habib Matin, PE, PhD Principal Engineer— Water Resources Attachments: Figure 1 — Recommended CIP Locations and Flood Extents Figure 2 — Profile of Water Surface Elevations Resultant of CIPS TM/SJ/HM Amec Foster Wheeler Environment & Infrastructure, Inc. January 2017 Project No.: 661 M-128571 Papa9 K:I1 I29¢D\12&57\12&571\CIPLatle6Channel6 CIP4Mr-Final.Doox Channel Recommended Capital Improvement Projects Springfield, Oregon REFERENCES Amec Foster Wheeler, 2014. Channel 6 Stormwater Master Plan. Prepared for the City of Springfield, Oregon by Amec Foster Wheeler Environment & Infrastructure, Inc. August 28, 2014. Amec Foster Wheeler, 2016. Engineer Report and Narrative for Channel 6 Letter of Map Revision (LOMB). Prepared for the City of Springfield, Oregon by Amec Foster Wheeler Environment & Infrastructure, Inc. August 12, 2016. Amec Foster Wheeler Environment & Infrastructure, Inc. Project No.: 661 M-1285]1 January 2017 K:\120WI2MI2&6TIM71\CIPLe 6Channel6 CIPLetter Final.Docx Page10 Chamels TABLE 7: NATURAL CHANNELS AND FLOODPLAINS 8-A-13 ODOT Hydraulics Manual HYDRAULIC ROUGHNESS (MANNING'S n) VALUES Minimum Normal Maximum Channel A. Minor streams (top width at flood stage less than 100 feet) 1. Streams on plain a. Clean, straight, full stage, no rifts or deep pools 0.025 0.030 0.033 b. Same as above, but more stones and weeds 0.030 0.035 0.040 c. Clean, winding, some pools and shoals 0.033 0.040 0.045 d. Same as above, but some weeds and stones 0.035 0.045 0.050 e. Same as above, lower stages, irregular slopes and 0.040 0.048 0.055 sections with more ineffective flow area f Same as d, but more stones 0.045 0.050 0.060 g. Sluggish reaches, weedy, deep pools 0.050 0.070 0.080 h. Very weedy reaches, deep pools, or floodways with heavy stand of timber and underbrush 0.075 0.100 0.150 2. Mountain streams, no vegetation in channel, banks usually steep, trees and brash along banks submerged at high stages a. Bottom: gravels, cobbles, and few boulders 0.030 0.040 0.050 b. Bottom: cobbles with large boulders 0.040 0.050 0.070 B. Hoodplains 1. Pasture, no brush a. Shortgrass 0.025 0.030 0.035 b. High grass 0.030 0.035 0.050 2. Cultivated areas a. No crop 0.020 0.030 0.040 b. Mature row crops 0.025 0.035 0.045 ODOT Hydraulics Manual 8-A-14 Channels ODOT Hydraulics Manual - HYDRAULIC ROUGHNESS (MANNING'S n) VALUES Minimum Normal Maximum Channel c. Mature field crops 0.030 0.040 0.050 3. Brush a. Scattered brush, heavy weeds 0.035 0.050 0.070 b. Light brush and trees, in winter 0.035 0.050 0.060 c. Light brush and trees, in summer 0.040 0.060 0.080 d. Medium to dense brush, in winter 0.045 0.070 0.110 e. Medium to dense brush, in summer 0.070 0.100 0.160 4. Trees a. Dense willows, summer, straight 0.110 0.150 0.200 b. Cleared land with tree stumps, no sprouts 0.030 0.040 0.050 c. Same as above, but with heavy growth of sprouts 0.050 0.060 0.080 d. Heavy stand of timber, a few down trees, little 0.080 0.100 0.120 undergrowth,flood stage below branches e. Same as above, but with flood stage reaching 0.100 0.120 0.160 branches C. Major streams (top width at flood stage more than 100 feet). The n values are less than those of minor streams with similar description because banks offer less effective resistance. 1. Regular section with no boulders or brush 0.025 ..... 0.060 2. Irregular and rough section 0.035 ..... 0.100 ODOT Hydraulics Manual - &73ii Transfer of Easements and Right of Way d KNOW ALL MEN BY THESE PRESENTS, That Rainbow Water District, a I �} municipal corporation, in Lane County, Oregon, grantor, in r consideration of the acceptance by the City of Springfield, a uniclpal cooperation, in Lane County, Oregon, grantee, and the and maintenance by grantee of the dra inagew.,y within the ease- ments and right of way hereinafter men*ioned, grantor does hereby i grant, bargain. soli and convey unto the grantee, its successors and assig, all title. rights and easements grantor acquired by the following documents recorded in Lane County Deed Records in Lane County, Oregon: rEasement granted by Kenneth L. Montgomery and Imagene G. Montgomery recorded Feb[uery IL, 1966 on Reel 281 D, Clerks Reception No, 36422, )Easement granted by R, M. Baker and Marian Raker recorded February 11, 1966 on Reel 281 D, Clarke Reception No. 36428, Easement granted by Margaret A, Crlstensen recorded February 25, 1966 on Reel 282 D, Clerks Reception No, 38032, r,Bargain and Sale Deed granted by Pioneer 'Title Cumpany of Lane County corded February 25, 1966 un Reel 282 D, Clerks Rece pilon No. 38022, Easement granted by Keith A. Wardell and Shirley D. Wardell recorded February 14, 1967 on Reel 336 R, Clerks Reception No75106, Easement granted by George E. Cook, at. and Mary S. Cook recorded February 14, 1967 on Reel 336 R, Clerks Reception No. 25102, Easement granted by John W. nichardson. Miriam D, Richardson, Bernard D. His ¢, Sharon Hiatt and George W. Stephens recorded on February 14, 1967 on Reel 336 R. Clerks Reception No. 25108, Easement grante,: by Donald M. Lee and Marilyn A. Lee recorded February 28. 1961 on Reel 331 R, Clerks Reception No. 16565, Easement granted by Robert M. Pearson and Rese M. Pearaon,recorded April 14, 1962 an Reel 342 R. Clerks Reception No. BL469, Easement granted by Jahn J. Jensen and Kathryn M. Jensen ¢corded April 14, 1967 on Reel 342 R, Clerks Reception No. 81482, Easement granted by Rase B. Shelley by Wilfred L. Wafter, UW.Fdi.S, recorded April 2, 1965 on Reel 263 D, Clerks Reception No, 98465, Easement granted by Estate of Ralph S. Shelley, Deceased, by Wilfred L, Walter, Administrator, recorded April 2, 1965 on Reel 263 D, Clerks Reception No, 98466. ,i Easement grantee by Ned Baker and Robert M, Artz recorded March 12, 1965 on Reel 261 D. Clerks Reception 95402, b/ Easement granted by Betty George recorded March 12. 1965 on Reel 261 D. Clerks Reception No. 95403, f Easement granted by Donald B. Kempf and Erma L. Kempf recorded March 12, 1965 on Reel 261 D, Clerks Reception No. 95404, 8921 Easement Transfer page 2 --------------- Easement granted by Walter J, do fie and Arda C. Raffle r0 corded March L2, 1965 on Reel 261 0, Clerks Reception Ne, 95405, VIEasement granted by Otto L1. Stratton and Loris I. Stratton ncord,d March 12, 1965 on Reel 261 D, Clerks Reception No. 95406, iEasement granted by Harvey E. Hermon and Nei11e M. Harmon recorded March 12, L965 on Reel 261 D, Clerks Reception Nu, 95407. �. Easement granted by Harvey E. :larmon and Nellie M. Harmmi vsecreted March 12, 1965 on Reel 161 0, Clerks Reception No, 95408, !j Easement granted by Rose B, Shelf, by Wilfred L. Walter. Guardian. recorded May 1L, 1055 on Reel 265 D, Clerks Reception No. 2765, ^Easement granted by Arnold Alba, re and Louise ql M1ev Cs recorded May 7, 1965 on Reel 264 D, Clerks Reception Na, 2412, A Easement granted by Renray, Tue., an Oregon Corporatton, recorded April 12, L965 on Reel 269 0, Clerks Receptiom No. 99015 Done by order of [hc g[entor's board9� directors with its corporate seal attached [his —day n /v� Q x , 1920 l ... , RAINBOW WATER DISTRICT by or attest far' State of Oregon, Con v ty of Lane, a. /VI' / 1 , 1970 personally appeared X"N C. 1.0", and TCkSa n, C j'rf who hens, duly wer. , say they e e she chairs.5 and secretary, respectively, of, Rainbow W.1District, a en tcipal co rp0mci.n in the State of Oregon, and the seal affixed to the foregoing instrument is the corporate seal of said corporation and that said instrument was signed and sealed on behalf of said corporation by authority of its boned of directors, and they acknowledged said inst,ment to he the free act and deed of Rainbow Water District. Before at i No [ery p c for Oregon My Commission Expires: Q r /%7/. If P, 8921 Easement Transfer Page J ----------------- A,—,f,d by order of the to—r, C til of he City of Saringfrc I with the seal of said city artacha, this day of M q ✓ 1970. CITY OF SPRINGFIELD, OREWN by \�ti T! ✓� 1 I:l ��Lv C1— [� STATE OF ORHWN ) 'Coan cy of Lane j On [his /;:. day of L970, beth-, m appeared JOHN E. MoCU1.LEY and N. 1.. PUU " to an personalty known, who being duly sw n did say that he the said JOHN E. MCCULLEY is the Mayor and hethe said N. L. TEAGUE is the City Recorder of the Cl EY OF SPRINGFIELD and that the seal affixed tc the foregoing ins[rumenL is he corporate s aL of said City and [hat he Lnstru- mens was signed and sealed in behalf of the City by authority of its Co.. Council and JOHN E. MCCULIEY and N. L. TEACUE acknow- Ledged said instrument to be the free net and deed of tae City of Springfield, Before melip. Notary Public for Oregon My ea'aaission expires: f LANE COTJN I Y State of oregon in the Matter of a ,O-Llhty Road Road No 3 File No Account 12eioc¢�ieti of Filed JUvwt 8 f 1849 3s_ 3 01 Recored Commissioner's Reel E�r M99-05 R06LCL BOOM 3 palre 5/7 r"7 �Y IR 7 4'4 (A't .4 n �ty Commissioners Court - Term, !89% Judlclal Day. .._ ....._.�.,..�. .ter � � t 4 � ` . yy�,�! e -Y !� �R!!Lf(sr 1 6 tu.�i!//�•r «.�� ` }(a 4�r < L� .ili�«yf. �1 / 7�.r/jLr"Pa e�L. A—V D.�. j .v1 G��—•moi. rL _ _a�L. vQ��t.-ac-•Viy'a[�. f.� �-t�-.l� Q_��� ,�„ ,d ]��7f ", n-. .Yef.t., -}t-e. 4�a�(1�7./L".� ✓Y.6LIVI—w b �a 4tti� .cam L I& ALI 7J ! 7M %%r►L f� d :: v 71 �yL Q� GZ... .n q �as.ia!- G rs yc 37 76f /liYyE(it.a� Tom., `/ .Trwti.a'e t c. Cil*J ,o� 7j-, 7r� /Q oLtt-s++C.v G9� .moi 23i:i 5 I 6 799 eQ...w.v 6 iC o J -2-d-' f. MAI �;o the YlonoralalE the .County Courl of j,anE County,. STATE OF OREGON: We the undersigned, householders of the County of Lane, State of Oregon, residing in the vi inity of'the proposed Road hereinafter described, respectfully petition your Honorable Bodzr tonlocate:a County Road as follows, to wit: .7tic, ... ale,,:.,u�. �l✓li, ,t',. rt,... --tF .p£'^:+,4/... 2fu... <i5's.�ct. ��1.. .t.•�,�-,•; .. J� -t /-L-..��./!/p✓:�`:..,/ _ Duct 2Q �•. NAMES. VdklEs. /E77 `-'_u_ 2zA /fti .;,, �✓' ry�s n_ a ur/ L_.:, _� a� ,.,.;,-ce, :,� x� ,s_,.� L�.a ss- er //° .33'�y�_ I,$S �--_eMd •q �`r/-2�,...e-c, fbC- .LC'o+-,-u 2.D /Lf aL�84 ci � �/✓, li. c+,•Y '�..1 ...a. w.�..Gd c. i�Ry 2� e�..��4 L a/+r- �u l- A.�[u..arv4"GJI.Fe.Csi-w-n.�«.�.+4.. U -eA, r..:..,.f 18.9__._,......: �' --- A ........ .......... . ... .......... ... .............. 18.9__._,......: In fhe Qoanfy Qoarf of fhe Sfafe of Oregon, Z dor the Qc)unfy of Lane, In tiw matter of the petition and, others for a County Road. S�;Pze O _4gea'0v,1 S sa. COUNTY OF LANE, j To the Zlonbrable Corenty Courtot the State of OreVore, for the County of Lane : Thr undersr ncrl, who wereduly apiviinted at The -ktA= terra i.nthe year f,i 789 .at the above entitled coact, as r ieoers of the road prayed for in shore clamed 1I potiteora of and others, hereby report That we inrt,rxt..t[. „ „_k?.,,,c`=, on, the.. .. L_2,."_.f.... dau of- 41, .._— 189.x..__-..., that being the tinge and place presoribc-d far such meeting by the court, and, after laking air oath oitla al& and irnpartially to discharVr the duties o our a roast f � /� I J ! / � /� PF ?hent, which oalh is herewilh filed, we took to our assistance and /-t).r.2,P.=yas claa;n, bearers. and ...... as marker, and proceeded to view .surrau, and.7a!l ou.d said road'as prayed for in, said th petition, as near ccs is our opinioia, a pond road can he nazde at a reasono.ble expea se, .7 takin,s into con..siderali,on, the Wility. cona;enieraee mild ineont c nience and expense which Will resrelb to individacals as melt as to the 7niblic, if such road shall be established anal opened. We, also caused�. "'4 Aw. .' -F . the sur-roeyor cippoircted /%,r that pur- pose, to surrey the nripiwd road, cinder our div eetion, and ra.ased the proposed road to be eonspieuoastrl nuanced throughout, and thr, corners and diyta.ncesih,vrenrz noted, all in the nzareaer reryraired by lav'. Rrferenre for jrar6iea.Ga:rs of said surzvgf an hereby rn ado to the plat and surrey of said prapnsed marlnurde by --Q,'4. mild herewith ftled. We are of the opinion That said proposed roadshoatd __ -.. belfs£abli P ad as -esoribedn, esa�id7P7.rrt mild sirrrnrf, for ?h,3frtlaraine-retcso;v ni �dz !0/ v ///.!!//. L.•i:.. �__xr�.. ?i. ...�a.e.vs-f__ �/ 'm..�w-e_-_ �z�.ti. ___4c�-.-�� _a.a�Lu- :"fin. nit, STATE OF OREGON, } ss. County of Lane.J. I, ..... _. __._: _ ._::being first duly sworn, on oath sap, that I leave posted Four notices, (a copy of whichis hereunto annexed) of the proposed road, in the following places, to -wit _.._S�. ... ....... ..._. ....................._............._.:._..................._................ .............. ,..............._.... .. and one at the Court House door in Eugene said Lane Comity and State of Oregon, thirty days prior to the presentatipnyof petition herein, and that all of said petitioners are house- holders residing in the picinity of said proposed road, in, said Lane County and. State of Oregon. _ Subscribed and sworn to before me this _._:...day of ...... A. D., x8q..... ._ � q � C o p H- O n � C S3 Foa d nom. o _. � ip. Tqs. <{_.dge.vens Ma Sim ed.xa 99Ze (lloasZ er a f f/ .A-4 Ci^[s - i'to cud Al-. u09 South. L.ne. Sferv....i pa.., 4Z.^b P�F'�ca�"3Gb 09