HomeMy WebLinkAboutCorrespondence PWE 4/4/2006
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Memorandum
City of Springfield
Subject:
April 4th, 2006
Jim Donovan, Urban Planner
Matt Stouder, E1T, Civil Engineer-in- Training
SU82005-00047, Legacy Estates Subdivision
Date:
To:
From:
I have reviewed the materials provided with the subject application. The recommended
findings and conditions outlined below are provided for your use in preparing the
land-use decision.
. SANITARY SEWER
Finding: Section 32.100 of the SDC requires that sanitary sewers shall be installed to
serve each new development and to connect developments to existing mains.
Additionally, installation of sanitary sewers shall provide sufficient access for
maintenance activities.
Finding: The applicant has proposed extension of an 8 inch public wastewater line with
service laterals to serve all lots within the development. The connection to the existing
public system is at the proposed street connection of Vera Street. The existing system in
Vera Street is a "dry" system. .
Finding: The applicant has signed an annexation agreement with the City of Springfield
(recording number 2005-020292). It is identified in this agreement that the existing
public sewer system in Vera Street is not connected to the remainder of the public
sanitary sewer system, and is therefore not useable until such time.
Finding: Per the annexation agreement, the City of Springfield plans to construct
necessary sanitary sewer services, including a lift station, a sewer main in Vera Street,
and a sewer main in 19th Street, to connect the proposed development to the public sewer
system. These improvements are planned to be placed into service in August, 2006, but
the City does not warral)t or guarantee that service will be available y that date.
Finding: Section 2.02.1 ofthe City's Engineering Design Standards and Procedures
Manual (EDSPM) states that when land outside a new development will logically direct
flow to sanitary sewers in the new development, the sewers shall be public sewers and
shall normally extend to one or more of the property boundaries. The applicant has
proposed extension of an 8 inch public sewer line to the southerly property boundary in
. both 16th and 17th Streets.
Condition: As required by the City and agreed to by the applicant in the signed
annexation agreement (recording number 2005-020292), issuance of building permits for
construction of dwellings on the property will be withheld until such time as the
downstream sewer improvements have been constructed and placed into service by the 0
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STORMW A TER MANAGEMENT
Finding: Section 32.110 (2) of the SDC requires that the Approval Authority shall grant
development approval only where adequate public and/or private stormwater
management systems provisions have been made as detennined by the Public Works
Director, consistent with the Engineering Design Standards and Procedures Manual
(EDSPM).
Finding: Section 32.110 (3) of the SDC states that a stonnwater management system
shall accommodate potential run-off from its entire upstream drainage area, whether
inside or outside of thc development. Per the signed and recorded annexation agreement
(2005-020292), the applicant is responsible to construct a public storm water management
system to collect, treat, convey and discharge stonnwater from the subject property and
all upstream tributary areas. .
Finding: Section 32.110 (4) of the SDC requires that run-off from a development shall be
directed to an approved stonnwater management system with sufficient capacity to
accept the discharge. Section 32.110 (5) of the Springfield Development Code (SDC)
requires new developments to employ drainage management practices, which minimize
the amount and rate of surface water run-off into receiving streams, and which promote
water quality.
Finding: To comply with Sections 32.110 (3), (4) & (5) of the SDC, and the annexation
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agreement, stormwater runoff from the site will be directed into a series of curb inlets,
pipes, and a large vegetative water quality swale prior to discharge into a tributary slough
of the McKenzie River. Runofffrom the streets will discharge into the existing 24 inch
'public stonn pipe on tax lot 400 prior to entering the swale.
Finding: The off-site improvements associated with the public stonnwater system for this
subdivision include construction of a large water quality swale, a drainage swale, and a
48 inch storm pipe. The proposed swales will be located along the south and west
property lines of tax lot 400. The water quality swale will transition into the drainage
swale after approximately 100 feet from the subdivision outfall. Due to topographic
constraints, the drainage swale will discharge into the 48 inch pipe system prior to
crossing Harvest Lane and entering the slough.
Finding: The City of Springfield provides routine maintenance for stonnwater quality
features (i.e. swales) that drain water from public rights-of-ways. Maintenance
performed is for "functionality" to ensure a properly working system; aesthetic
maintenance is not provided. As part of the Public Improvement Plan process, the
applicant will be required to enter into a maintenance agreement with the City, whereby
the City will provide routine functional maintenance of the proposed swale.
Finding: The proposed elevation of the 48 inch piped system outfall into the slough
(north of Harvest Landing) is shown to be 435,67 feet per submitted plans. The 100-year
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floodplain elevation as shown on the Flood Insurance Rate Map (FIRM) # 1153 of2975
is approximately 450 feet in elevation. In a separate study prepared by David Evans and
adopted by the City of Springfield (McKenzie River Floodplain Assessment), the 100-
year floodplain elevation is shown at approximately 446 feet. For the purposes of
satisfying article 27 of the Springfield Development Code (Floodplain Overlay) for
building construction, the applicant shall be required to use floodplain information based
. on the FIRM map.
Finding: Information contained in the McKenzie River Floodplain Assessment shows the
approximate elevation of the McKenzie River to be 445 feet during a I O-year flood event.
The flow line at the 48 inch piped outfall is shown to be 435.67 feet per submitted plans.
The proposed flow line where the swale enters the 48 inch pipe is 436.77 feet. The swale
is proposed to be 2 feet deep, bringing the top of the swale to approximately 438.77 feet.
[n the event the McKenzie River water level is higher than 438.77 feet, water from the
River will drain into and onto tax lot 400, and then onto adjacent private properties.
Finding: A backflow preventer or equal will keep water from the McKenzie River out of
the proposed public system, but does not serve to drain the public system into the river
when river levels are high. To ensure adequate drainage of the public system to the river
during periods of high water, the water surface elevation of the public system needs to
build up to an elevation higher than the river water surface (to create a pressure
difference to drain the runoff). This will not occur with the swale as proposed, because
the swale depth is only 2 feet in elevation, leaving water to flow out of the swale when
the water depth is greater than 2 feet.
Condition: At the time of PIP review and prior to Final Plat, the applicant shall enter into
a maintenance agreement with the City of Springfield, whereby the City will provide
routine maintenance for functionality of the grassy swale/detention pond serving the
subdivision. The City will provide the template for the maintenance agreement.
Condition: During the PIP design process, the applicant shall install a backflow prevention
system acceptable to the City Engineer at the proposed outlet of the 48 inch public storm
piped system at Harvest Lane. Details of this system shall be shown on the Public
Improvement Plan.
Condition: During the PIP design process, the applicant shall berm the swale as necessary
to create adequate head to allow stormwater runoff to drain to the proposed 48 inch piped
outfall. The applicant shall design the berm to an elevation above the I O-year flood
elevation of 445 feet as shown in the McKenzie River Floodplain Assessment.
WATER QUALITY
Finding: Under Federal regulation of the Clean Water Act (CWA), Endangered Species
Act (ESA), and National Pollutant Discharge Elimination System (NPDES), the City of
Springfield is required to obtain, and has applied for, a Municipal Separate Storm Sewer
System (MS4) permit. A provision of this permit requires the City demonstrate efforts to
reduce the pollution in urban storm water to the Maximum Extent Practicable (MEP).
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Finding: Federal and Oregon Department of Environmental Quality (ODEQ) rules
require the City's MS4 plan address six "Minimum Control Measures." Minimum.
Control Measure 5, "Post-Construction Stonnwater Management for New Development
and Redevelopment," applies to the proposed development.
Finding: Minimum Control Measure 5 requires the City of Springfield to develop,
implement and enforce a program to ensure the reduction of pollutants in stormwater
runoff to the MEP. The City must also develop and implement strategies that include a
combination of structural or non-structural Best Management Practices (BMPs)
appropriated for the community.
Finding: Minimum Control Measure 5 requires the City of Springfield use an ordinance
or other regulatory mechanism to address post construction runoff from new and re-
development projects to the extent allowable under State law. Regulatory mechanisms
used by the City include the Springfield Development Code (SDC), the City's
Engineering Design Standards and Procedures Manual (EDSPM) and the future
Stormwater Facilities Master Plan (SFMP).
Finding: As required in Section 31.050 (5) of the SDC, "a development shall be required
to employ drainage management practices approved by the Public Works Director and
consistent with Metro Plan policies and the Engineering Design Standards and
Procedures Manual."
Finding: Section 3.02 of the City's EDSPM states the Pubic Works Department will
accept, as interim design standards for stormwater quality, water quality facilities
designed pursuant to the policies and procedures of either the City of Portland (BES), or
the Clean Water Services (CWS).
Finding: Section 3.03.3.B of the City's EDSPM states all public and private development
and redevelopment projects shall employ a system of one or more post-developed BMPs
that in combination are designed to achieve at least a 70 percent reduction in the total
suspended solids in the runoff generated by that development. Section 3.03.4.E of the
manual requires a minimum of 50 percent of the non-building rooftop impervious area on
a site shall be treated for stonnwater quality improvement using vegetative methods.
Finding: To meet the requirements of the City's MS4 permit, the Springfield
Development Code, and the City's EDSPM, the applicant has proposed a vegetative
water quality swale approximately 100 feet long, followed by a drainage swale
approximately 350 feet long. A planting plan/seed mix has not been proposed for the
swale.
Finding: The vegetation used in the swale will serve as the primary pollutant removal
mechanism for the storm water runoff, and will remove suspended solids and pollutants
through the process of sedimentation and filtration. Satisfactory pollutant removal will
occur only when the vegetation has been fully established.
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Condition: Prior to approval of the Public Improvement Plan, the applicant shall submit a
proposed vegetation plan/seed mix for the proposed water quality swale. The planting
plan/seed mix shall meet the requirements of the City's interim design standards as
required in Section 3.02 of the EDSPM. The City of Portland stormwater management
manual may be referenced for design.
Condition: To ensure a fully functioning water quality system and meet objectives of .
Springfield's MS4 pennit, the Springfield Development Code and the EDSPM, the
proposed water quality swale shall be shall be fully vegetated with all vegetation species
established prior to approval of Final Plat. Alternatively, is this condition cannot be met,
the applicant shall provide and maintain additional interim erosion control/water quality
measures acceptable to the Public Works Departmentthat will suffice until such time as
the swale vegetation becomes fully established.
PUBLIC STREETS. SIDEWALKS & IMPROVEMENT ARGEEMENTS
Finding: The applicant has proposed construction of public streets, curbs, gutters and
sidewalks for the proposed development, to be constructed with the public improvement
project.
UTILITIES. EASEMENTS AND RIGHTS OF WAY
Finding: Section 32.120 (3) of the Springfield Development Code requires each'
development area to be provided with a water system having sufficiently sized mains and
lesser lines to furnish adequate supply to the development and sufficient access for
maintenance. Springfield Utility Board coordinates the design of the water system within
Springfield city limits.
Finding: Section 32.120 (5) of the SDC requires applicants proposing developments
make arrangements with the City and each utility provider for the dedication of utility
easements necessary to fully service the development or land beyond the development
area. The minimum width for public utility easements adjacent to street rights of ways
shall be 7 feet. The minimum width for all other public utility easements shall be 14 feet.
Finding: The applicant has proposed 7 foot public utility easements along the frontage of
the proposed streets within the subdivision, satisfying Section 32.120 of the SOC.
Additionally, a 14 foot public utility easement has been proposed between the property
lines oflots 7and 10, and 8 and 9, to accommodate the proposed public sewer line.
Finding: The applicant has proposed a 40 foot Public Drainage Easement to cover the
proposed open channel drainage swale and associated 48 inch piped system located on
tax lot 400. The signed and recorded annexation agreement states that the easement
width for the open channel portion of the stormwater system shall be determined based
upon the design width of the channel plus 10 feet on one side and 25 feet on the other
side to accommodate maintenance and access by City personnel and equipment.
Finding: The proposed 24 inch stonn pipe exiting the subdivision to the north (between
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lots 16 & 17) is shown to be located in a proposed 20 foot public utility easelJlent. This
storm line will connect to the existing manhole located on tax lot 400. Maintenance
access to the existing manhole on tax lot 400 will be required such that routine
maintenance at the manhole can be accommodated. Thus, an access way, sufficient to
support maintenance vehicles, will be required, but has not been proposed.
Finding: Section 4.07.D ofthe City's EDSPM requires that access roads or other suitable
access ways for maintenance purposes shall be provided when channels do not about
public right-of-way. Thus, an access way, sufficient to support maintenance vehicles,
will be required, but has not been proposed.
Finding: The existing 24 inch stonnwater line located op the southeastern propel1y line
of tax lot 400 is shown to be located within an existing 14 foot public utility easement.
Documentation for this easement has not been provided, and City records do not verify
an easement in thi's location.
COllditioll: Prior to approval of the Final Plat, the applicant shall revise the proposed 40
foot Public Drainage Easement to comply with Section 1.4.3 of the signed and recorded
annexation agreement (recording number 2005-020292). Specifically, the drainage
easement shall be modified for the section surrounding the proposed open channel swale.
COllditioll: Prior to approval of the Public Improvement Plan, the applicant shall provide
a maintenance access way, located within the proposed 20 foot PUE between lots 16 &
17, to the existing stormwater manhole located on tax lot 400, sufficient to accommodate
maintenance vehicles.
COllditioll: Prior to approval of the Public Improvement Plan, the applicant shall provide
a maintenance access way, consistent with section 4.06.D of the City's EDSPM, located
within and along the entirety of the public easement for the open channel swale and 48
inch storm pipe, sufficient to accommodate maintenance vehicles. The access 'road shall
have a turn around located at the end of the road.
COllditi01l: Prior to approval of the Final Plat, the applicant shall submit documentation
verifying the 14 foot public utility easement for the existing 24 inch stormwater pipe
located on tax lot 400 has been recorded. If this easement has not been recorded, the
applicant shall be prepare the easement and record it with the Final Plat.
OTHER PERMITS
Finding: Section 35.040 (6) (n) ofthe SDC requires the applicant submit concurrently
with the application evidence that any required federal or state penriit has been applied
for or approved. The applicant has submitted a Joint Permit application to the US Army
Corps of Engineers (USACE) and the Oregon Department of State Lands (DSL) for work
to be done in the slough area for construction of the public stonn, sewer outfall (along the
northerly portion oftax.lot 400). Approval for this work has not been granted at this
time, and is pending approval from the USACE and DSL.
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Condition: Prior to approval of the Final Plat, and consistent with Section 35.060 (10) of
the Springfield Development Code, the applicant shall submit approved copies of
necessary required pennits to demonstrate compliance with Federal and State programs
and regulations for the work to be done in the slough area on the northern portion of tax
lot 400 for the proposed storm sewer system outfall system.
NOTE: The intent of this list is to give a developer insight about requirements related to
public improvements before they develop their property.
FEES AND PERMITS
. SYSTEMS DEVELOPMENT CHARGE:
Pay applicable Systems Development Charges when building pennits are issued for
developments within the City limits or within the Springfield Urban Grow~h Boundary.
(The cost relates to the amount of increase in impervious surface area, transportation trip
rates, and plumbing fixture units. Some exceptions apply to Springfield Urban Growth
areas.) [Springfield Code Chapter II, Article 11]
Systems Development Charges (SDC's) will apply to the construction of buildings and
site improvements within the subject site. The Charges will be based upon the rates in
effect at the time of pennit submittal for buildings or site improvements on each portion
or phase of the development.
SANITARY SEWER IN-LIEU-OF-ASSESSMENT CHARGE:
Pay a Sanitary Sewer In-Lieu-of-Assessment charge in addition to the regular connection
fees if the property or portions of the property being developed have not previously been
assessed or otherwise participated in the cost of a public sanitary sewer. Contact the
Engineering Division to detennine ifIn-Lieu-of-Assessment charge is applicable. lOrd
5584] .
PUBLIC INFRASTRUCTURE FEES:
It is the responsibility of the private developer to fund the public infrastructure. .
OTHER CITY PERMITS:
Encroachment Permit or Sewer Hookup Permit (working within right-of-way or public
easements) example: new tap to the public storm or sanitary sewer, or adjusting a
manhole. [The current rate is $130 for processing plus applicable fees and deposits]
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Land & Drainage Alteration Permits (LDAP). [Contact the Springfield Public Works
Department @ 726-5849 for appropriate applications/requirements]
ADDITIONAL PERMITS/APPROVALS MAY BE NECESSARY:
. Metropolitan Wastewater Management Commission (Pump station, sanitary
sewers 24 inches or larger)
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. Lane County Facilities Permit (If the project is within Lane County jurisdiction)
. Railroad ([fthe project crosses a railroad)
. Oregon Department of Transportation (If the project is within ODOT jurisdiction)
. Division of State Lands (Stonn water discharge, wetlands)
. Oregon Department of Environmental Quality (Erosion control (5 acres or
greater), pump station, storm water discharge, wetlands)
. U.S. Army Corps of Engineers (Stonn water discharge, wetlands)
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