HomeMy WebLinkAboutMiscellaneous PLANNER 2/16/2005
. .
PUBLIC WORKS DEPARTMENT
ADMINISTRATION
ENGINEERING DIVISION
ENVIRONMENTAL SERVICES DIVISION
MAINTENANCE DIVISION
TRANSPORTATION DIVISION
TECHNICAL SERVICES DIVISION
225 FIFTH STREET
SPRINGFIELD, OR 97477
www.ci.springfield.or.usldepLpw. him
wwwci.springfield.or.us
PUBLIC IMPROVEMENT PROJECT
CORRECTION LETTER: February 16, 2005
MOUNTAINGATE SUBDIVISION - PHASE 4
Land Development Eric Walter, Civil Engineer
Storm Drainage: Matt Stouder, EIT
PIP Construction: Don Branch, Sup. Civil Engineer
Transportation: Dean Bishop, Traffic Technician IV
SECOND SUBMITTAL
PROJ #: P30402
Plans and documentation as submitted was reviewed by City staff for Public Improvement
requirements. A red marked set of plans is included with this letter. Please return this red marked
set with seven (7) sets of revised plans and necessary documentation. In order to expedite
recheck, please include a response letter that corresponds to the item numbers below. Items 2
through 87 below are repeated comments from plan check letter dated 10/22/04. The repeated item
numbers correspond to the original numbering and only include those items that were not
completely addressed. Item numbers 94 through 115 are new items. In addition to addressing
each red marked comment on attached City marked plan set, the applicant is required to resubmit
plans addressing the following comments:
PUBLIC WORKS ENGINEERING
2. Submit applicable permits required by other jurisdictions. Please refer to City of Springfield Design
Standards and Procedures manual, Section 12.
Pending approval by all jurisdictions. DSL, Parks Dept, etc. Submit approved final mitigated
wetlands plans and documentation.
3. Submit a complete Erosion and Sediment Control Plan (ESCP) showing confomnance with City of
Springfield Design Standards and Procedures manual, Section 8. (Resubmit drawings reflecting
comments from LOAP staff and recent LOAP permit for permanent record). .
LDAP notes shall be updated so as to eliminate all conflicts with PIP plans for construction
work, sequence, and timing. Identify clearing limits on plan sheets 29 and 30.
6. Plat boundaries must be clearly identified on plans.
Jurisdictional boundaries are not clearly nor completely defined on plans for property lines,
plat boundaries, parks, home association open space, adjacent jurisdictions, etc. Please
completely show all jurisdictional boundaries associated with this project
7. Approval is required by Lisa Hopper in the Building Division regarding street addressing and
proposed street names, prior to PIP plan approval.
Pending Building Division approval. RECE~VED
. J~ lie, 05
ADMINISTRATION I TECHNICAL SERVICES / ENGINEERING: (541) 726-375BVi><: 541 736-1021
MAINTENANCE: (541) 726-3761 . FAX (541) 726-3621 TRANSPORTATIC!J: (541) 726-3753 . FAX(541 726-3781
ENVIRONMENTAL SERVICES.' (541) 726-3694 . FAX (541) 726-2309 \ rof 15 p~
.
.
13. Plans must be completely detailed with pavement details and plans shall clearly indicate limits and
dimensions for pan handle driveways, public access ways to parks, and any other common use
locations. These driveways and access ways must be constructed along with all other public
improvements so must be included on construction plans. (Example locations: Lot 5, parks, etc.)
Scale may be inappropriate for showing sufficient detail. Provide complete specifications
and plan dimensions for construction purposes.
14. Provide complete curb cut detailing on plans at all pan handle driveway locations, public access
ways to parks, and any common use access location.
Curb cuts at maintenance access are not shown. Please verify all locations.
16. Provide enlarged curb ramp details and dimensions.
Provide detailing showing conformance with City of Springfield Standard drawings.
17. Provide guard-rails at all hazardous locations (any drop-ofts or pond locations). Please include
construction details for guard-rails.
Work out required detailing directly with Transportation Division.
18. It is unclear what will be happening with Lots 117 through 126 along with road construction.
Complete and clear detailing needs to be included and/or clearly deleted from scope of work with
next submittal. .
All lots not being plated shall be coordinated with / approved by Planning, All lots not being
plated shall be deleted from plan set
20. In addition to storm and sanitary, the plans shall clearly indicate all utility locations, including but not
limited to water, power, cable, gas, etc.
Pending approval by all utility companies.
23. Structural analysis and design shall be submitted for proposed retaining walls. Plans must be
completely detailed for retaining wall design requirements.
Retaining wall design submitted is based on the 1997 UBC; however, this code is out of date.
The retaining wall design must use the Oregon 2004 Structural Specialty Code which is
based on the 2003 International Building Code with 2004 Oregon Amendments. Design
retaining wall surcharge for the AASHTO HS20-44 vehicle loading requirements. Retaining
wall design must be detailed for guard-rail and additional impact loading requirements.
24. Proposed detention / retention facilities shall control ex-filtration / percolation to pre-development
flow conditions. Please submit design showing conformance with EDSP storm water quality design
standards Section 3.01.0 through 3.03.4. The detention pond must be completely detailed and
conform with the City of Springfield Engineering Design Standards and Procedures Manual Section
4.12 and address items A. through E. Submit supporting calculations or documentation for
proposed clay liner.
Plans must be completely detailed with complete specifications for construction purposes.
26. Plans do not clearly indicate boundaries of the wet lands. Please provide clear boundary
information on plans for permanent record and for ensuring contractor can appropriately mark and
protect those areas. Please indicate what work will occur in the wet lands (ie, wetland areas to be
mitigated, 'etc) ,'c.... ",.~ t.,;
The propose~ mitig'atelhNetland area has not been shown on the 'plans. No indications of
, . , '. 'I ~ .,n ' '
. the proposed boundaries' have been shown.
MountainGate Phase 4
Page 2
2/l7/2005
.
.
27. Hydraulic Grade Lines (HGL) are shown on the profile drawings of the plans, but HGL calculations
have not been submitted. Please provide calculations to verify the elevations of the HGLs shown on
the profile drawings. Plan profiles are showing the pipes being surcharged at several locations and
will need to be redesigned to be contained completely within all pipes.
Engineer has not complied with comment 27. There are several places on the plan set where
the 10-year HGL elevation exceeds the crown of pipes. The system shall be re-designed to
ensure the 10-year HGL is contained completely within all pipes.
28. Profile sections are showing pipes SD109, SD107, and SD155 surcharging for 10 year storm.
Please submit complete analysis and design showing hydraulic grade line information for ten year
storm for pipe design requirements (SDC 4.03.4) and 25 year analysis for structures (SDC 4.03.5).
Will require two separate analysis unless all pipes and structures are not surcharged with 25 year
event.
The above mentioned pipe sections are still surcharged during a 10-year event, and a 25-year
event has not been performed, showing a minimum of 1 foot of freeboard between the top of
structure and the HGL.
30. All manhole structures shall be designed and detailed such that all items 1 through 11 have been
addressed per SDC 4.04, specifically item 3 that requires all crowns to be aligned at the same
elevation.
Sheet 2 shows 18"storm drain pipe whose crown is not connected to a 24"storm pipe.
36. Include flow line elevations for all 10 inch storm pipes coming into manholes from the associated
curb inlets.
The proposed note to have "storm drain laterals connect to the manhole 0.1' above the outlet
pipe invert" that was added to the cover sheet is insufficient. The crowns of the lateral pipes
should match the crowns of the main storm pipes at the manhole structure. Flow line
elevations shall be called out on the profile drawings for the storm drain laterals, and rim
elevations shall be included on the plan drawings.
37. Bay Saver manholes are proposed in several locations of the subdivision to satisfy water quality
requirements. The applicant shall include a detail drawing of the Baysaver unit with the plans and
provide the model number to be used (1 K, 3K, etc.) in the construction notes. Note: ensure the
model selected is large enough to bypass flows from the 25-year storm event. Provide complete
documentation from the Baysaver manufacturer that will clearly demonstrate that volumes;
velocities, and flow rates are acceptable. The Baysaver construction details shall be' drawn to scale.
A detail drawing of the Baysaver manhole shall be included with the plan set, and referenced
with the construction notes.
40. Include a construction note on the plans for all areas where trench drainage control will be
implemented (area where trench is over 10%). Details are currently included with the plans.
In addition to the note placed on the cover sheet, construction notes shall be placed on the
plans in all areas requiring a trench train (over 10%).
42. The jurisdictional drainage way, located on lots 99, 106, and MountainGate Drive, has not been
shown on the plans. This drainage way shall be shown on the plan set, and accommodations shall
be made to convey water from the drainage way and into a receiving system.
Accommodations still need to be made to convey water from this drainage swale across
Mountaingate Drive. Water will still collect and flow in this drainage way, regardless of
whether or not it is a "jurisdictional" drainage way. This may affect the layout/grading of the
proposed lots.
MountainGate Phase 4
Page 3
2/17/2005
44. Clearly show the PhYSicaltation of the proposed swales on the! set. Include an accurate
depiction on the plans showing dimensions, such as widths, lengths, and contour lines.
The swale design as shown on the plan set is not complete. A complete profile of both
swales (over their entire length) shall be clearly shown on the plan set, indicating where the
break between the 0.5% sloped water quality swale and 10% conveyance swale is.
.
46. Detail drawings shall be submitted showing inlet and outlet structures at the proposed swales.
Include riprap for energy dissipation where necessary (swale inlet). Detail the outlet grates as well.
This comment has not been adequately addressed. A blow up detail, clearly depicting how
the piped system will enter the swales, and where rip rap will be placed shall be included on
the plans. This can be a standard detail for more than one inlet. How will the energy be
dissipated when entering the swale? Plans indicate pipes discharging into the swale at a
right angle to flow.
47. Erosion and scour are of concern due to high flow velocities resulting from larger storm events.
Provide swale velocity information for the 25-year storm event.
The submitted calculations in the proposed swales indicate very high velocities in the 10%
swale sections. The proposed to standards set forth in Table 4-2 of the Engineering Design
Manual. Per this table, rip rap lining is required for runoff conveyance. A separate detail
for the steep swale sections is required. Additionally, the bend in the 0.5% swale shall be
reinforced with rip rap or alternative, to provide stability during high flow event, and limit the
potential for erosion, scour, and/or blowout.
48. Flow spreaders will be required at the inlet of each proposed swale, and at intervals of no more than
50 feet, to dissipate velocity.
A standard detail drawing is required for proposed flow spreaders. Rock material is used for
standard check dams, and is preferred here. Adequate provisions have not been made to
dissipate runoff prior to entering wetland areas. Flow shall be dissipated and spread out
prior to discharge into wetlands areas. A letter from the wetlands consultant shall be
submitted acknowledging the flow spreader design and high velocities are acceptable, prior
to discharging into the wetlands.
50. Clearly show the 21 and 12 inch orifice locations for the detention basin outlet structures on the
outlet structure detail drawing. Provide a separate detail for each outlet. Provide orifice detail that
includes vent with over-flow.
The vent with overflow detail has not been addressed.
52. Include 10 year, 25 year, and 100 year HGL's on section view through detention pond at outlet.
The 100-year HGl has not been provided on section view.
53. Provide complete erosion control detailing at pond outlets conforming with City standards.
Engineer has not complied with this comment. Erosion control is needed at the outlet of
each pond pipe. A detail drawing is needed, clearly showing how the pipes interact with the
energy dissipation structure. Additionally, please add a note to the end of the 24 inch pipe to
cap the pipe. Need pipe caps at both ends.
54. Clearly detail the stainless steel plate for each pond outlet. Show how the plate will be anchored to
the outlet structure, and include the locations of the bolts, etc. Show the orifice locations on this
structure. (Please consult with Greg Fershwieler of the Maintenance Division for ensuring this
removable plate will meet their requirements).
The locations of the orifice shall be clearly shown on the detail drawing.
MountainGate Phase 4
Page 4
2/1712005
.. 55. Include a detail drawing t& used at the outlet locations for both .15 and 24 inch storm pipes
exiting the detention pond. The details shall clearly depict energy dissipation measures (riprap), as
well as show contours and the receiving system to which water will be discharged. Provide flow line
elevations of the existing systems.
Engineer has not complied with this comment.
57. Specify a water quality seed mix and planting plan for the proposed detention system.
Engineer has not complied with this comment. Seed mixes proposed for water quality
swales only. No seed mix proposed for low flow pond area.
58. Identify how the proposed detention pond will be lined to prevent infiltration of stormwater into the
fractured basaltic rock below the pond surface. Specific concerns include water infiltration and
migration down-gradient where localized flooding may occur. Submit concurrence letter from the
Geotechnical Engineer of Record regarding acceptability of proposed pond liner.
Engineer has not complied with this comment. The letter submitted by the Geotechnical
engineer is not complete, due to soil testing conditions which are based on previous tests in
an area outside of the pond limits, prior to reaching finish pond grade. A pond liner option
still needs to be presented. Identify how pond will be lined, and provide a standard detail
drawing on the plans.
59. Sheet 3 - Please revise wastewater manhole # 10 so that 0.1 foot of fall will occur across the
manhole. The invert in and invert out elevations are the same at 735.60 feet. This occurs in the
same manhole on sheet C12 as well.
Repeat comment.
68. Sheet 20 - Provide a detail drawing showing the storm sewer outlet to the mitigated wetland.
Indicate the pipe size discharging to the wetland, and the type of outlet structure to be installed.
The rip rap apron needs to be moved behind the PUE; This may involve extending the pipe.
70. Sheet 21 - Provide a detail drawing showing the proposed outlet from the mitigated wetland area.
Indicate what type of drain will be installed and how if will function wlo clogging.
Clearly detail how the outlet pipe will be situated in relation to the wetland bank. Currently,
all that is shown is a pipe stub in white space. No contours have been provided, no
indication of how the pipe is situated regarding bank, nor distance from bank, pipe extends.
71. Sheet 25 - Provide a detail drawing for the 24 inch storm sewer outlet into the existing ditch. Show
the existing ditch on the plans and profile. Specifically, show contours on the plans at the location of
the outlet. Show flow lirie information on the profiles. Indicate how energy dissipation will occur at
the outlet. .
Engineer has not fully complied with this comment. A blowup detail of this area is need,
showing how erosion and scour will be dealt with. Plans show pipe discharging into rip rap
at a 45 degree angle, and make no mention of discharging into an existing ditch. Contours
have not been shown, and the ditch is not shown on the plan drawings.
MASTER PLAN APPROVAL CONDITIONS
77. Condition 1: Prior to final public improvement plan or plat approval the applicant must submit the
following easement information: (a) An approval letter from SUB Water Department for the Phase IV
water system and easement locations. (b)The final plat shall show all existing and proposed
easements necessary to serve the site with public and private utilities.
Easements and clear jurisdictional boundary information must be included on the PIP
construction documents.
MountainGate Phase 4
Page 5
2/17/2005
78. Condition 2: The 12" line !essary to serve Phase IV must be co!ructed and accepted by SUB .'
Water and the City of Springfield.
Pending Acceptance
80. Condition 5: Prior to Public Improvement Plan approval trench drainage measures, or other
approved methods of handling flow of water in trench backfill, must be incorporated into all trench
sections with slopes exceeding 10 percent and elsewhere as required by the City Engineer.
The trench drainage detail provided on plan sheet 32 does not appear to clearly show applicable
locations on plans.
Repeat comment. Refer to comment 40 from above.
81. Condition 6: Prior to Public Improvement Plan approval, the final storm water system designs shall
be revised to comply with storm water and wetland flow analyses as required by the City Engineer.
The plan shall include:
e) Prior to or concurrent with the development of lots within Phase IV located South of Lots 1
through 49 and the North Cluster the applicant shall provide detailed plans for the detention ponds
proposed at the quarry park site.
Sub-comment (e) of this comment still applies. No detailed plans for the detention pond
have been submitted for review.
83. Condition 10: Prior to Public Improvement Plan approval, the final storm water system access
designs shall be revised to provide the following facilities as approved by the City Engineer:
a) A blanket maintenance access easement in favor of the City shall be recorded for the park
detention pond area and the open spaces containing the wetlands and upper drainage swale.
b) An all weather access road will be provided from MountainGate Drive to the inlet and outlet
facilities between the detention pond and the wetland mitigation area at the park site. The
access shall be a minimum of 12' wide, 80,000 Ib capacity and shall include a turn around and
Public Works keyed bollard for access control at a location identified by the Maintenance
Division during PIP design.
c) The access way between Lots 97-98 and 44-47 shall provide an access way to the open space
that is a minimum of 12' wide, 18% maximum grade and shall include a Public Works keyed
bollard for access control at a location identified by the Maintenance Division during PIP design.
Pending submittal
87. Condition 31 :a. Execute and record a joint-use access and maintenance agreements over all
areas of shared access proposed for: Lots 25, 26, 27, 28, 44, 45, and 46. Joint use panhandle
accesses with a minimum 20 foot width and private utilities shall be constructed during the public
improvement construction process.
Pending submittal
TRANSPORT A TlON (NEW COMMENTS):
94. Need a calculation for the vertical curve at station 17+01.52 to 17+51.52.
95. Need to show advance waming signing for Collier Drive approaching the intersection do to the
veriical curve between 10+25 and 10+75 not meeting sight distance requirements (Dean will put this
comment as a pari of the signing plan comments).
96. For the horizontal curves, I need to see the equation used for the calculation of the sight distance,
the stationing for each horizontal curve, and the sight distance for each Oust like it is shown for the
veriical).
97. Address all Transporiation notes and red-marked comments on plans.
MountainGate Phase 4
Page 6
2/17/2005
.
;UBLlC WORKS ENGINEERIAvEW COMMENTS):
.
98. Clearly show how lots 1 through 4 will be supplied with stonn and sanitary sewer service on plans..
99. Sheet 3 - Construction note 489 is missing from legend.
100. Sheet 16 - Please move the curb inlet at Station 30 + 56. 19 back so the stonn line can tap into the
adjacent manhole. Construction note 466 (which is missing from the legend) can be removed.
101.Sheet 19 - Please revise curb inlet so stonn line can tap into adjacent manhole. Please do this
wherever feasible in other places where curb inlet stonn lines can tap manholes. Add construction
note 210 to the legend.
102. Sheet 21- Construction note 40 indicates constructing a 5 foot sidewalk. The limits of CDnstruction
for this walk are not clear. Please clearly show the boundaries between the sidewalk to be
constructed, and future sidewalks.
103. Sheet 26 - Minimal cover is provided between the crossing of the two 24 inch stonn pipes. A
concrete saddle is required here. Please add a note to the plans and construction legend..
104. Energy dissipation has nDt been provided fDr or discussed regarding inlet sources for the detention
pond (specifically the wetland waterfall section and the 24 inch stDrm pipe from Mountaingate
Drive). Detail information is missing from the pDnd structure. Of specific CDncern is the potential
scouring effect due to high velocities from runoff, especially from the 24 inch stonn pipe. Water will
shoDt out of this pipe with much potential and kinetic energy (due to high velocity and about a 20
foot drop tD the pond bottDm), and potentially affect the pond outlet structures and pond bank. Rip
rap or an alternative equal will be required along the pond banks in these sections.
105.A CDncurrence letter shall be submitted from Wil/amalane, stating their understanding of the
proposed pond design (with relation to runoff water shoDting or cascading to the pond bottom from
the inlets), and that they accept the proposed system.
106.A profile drawing of the IDW flow pond/swale is required, along with a detail drawing (specific tD the
low flow pond/swale) showing all applicable dimensions of this feature.
107.A complete profile section is needed through both the detention pond and proposed mitigated
wetland. Details showing proposed subsurface structure, sDiI depth, etc. shall be submitted to the
City for review.
108.A copy of the wetland report (approved by the ACOE and DSL) for the proposed mitigated wetland
shall be submitted to the City fDr review.
109. The proposed mitigated wetland shall be clearly defined on the plans (show the limits of
construction and grading) and shall be labeled on the plans.
110. Lots 50 and 51 are being proposed over designated wetlands area. Submit documentation
showing these areas have been approved to be mitigated and revise plans as necessary.
111.Maintenance Department (Greg Ferschweiler) has requested ballards be installed at all
maintenance vehicle access pDints for future gates to limit only authorized vehicle access.
112. Submit landscape and street tree planting plans prepared by a licensed landscape architect.
Please include irrigation plans that address any remote island planting requirements.
MountainGate Phase 4
Page 7
2/17/2005
113.AII plan sheets shall be iluded in construction set and referenc~n index by sheet number
(including lighting, landscape, easement and jurisdictional boundaries, etc.).
.
114.Address all Public Works red marked comments as indicated on attached City marked plans. The
City red marked plan set must be retumed to the City with the next resubmittal.
115. Please provide a written response that describes how the plans and submittals have addressed
and/or complied with the comments included in this plan review letter.
After you had the opportunity to review this letter and the attachments, please contact me at your earliest
convenience at (541)736-1034 to arrange a meeting where we can go over comments in detail together.
Please feel free to contact me at anytime if you have any questions or need further clarification.
Sincerely,
Z~ tJ~
Eric Walter, Civil Engineer
Public Works Land Development Section
MountainGate Phase 4
Page 8
2117/2005