bld20100013_760 Aloha St-Storm_review_Checklist-1.xls
Stormwater Management Review Checklist
Date:1/22/2010
(For New Developments with > 5,000 sq ft of new impervious surface
Site:Holy Rosary Church
or North Edmonds Earth Subsidence and Landslide Hazard Area )
Address:760 Aloha St
By: Jerry Shuster, P.E.
CompleteIncompleteComments
1
Project Overview Narrative
The Storm drainage report must describe all "New" impervious surface. "New" impervious surface
is defined as any impervious surface created after created after July 7, 1977 that does not have
stormwater controls. The new impervious surface from the new parish building is well defined,
X
however, are there any other "new" impervious area on the site?
(A)Description of existing site (include area of site)
X
(B)Description of Proposed Development
X
(C)Discuss offsite drainage impacts to the site & from the site
X
(D)Nearest mapped surface water body where site stormwater discharges.
Discuss disposition of storm water runoff before & after development
X
(E)
Provide map showing general location of the site & geographical
X
(F)
features
X
(G)Description of predeveloped assumptions for site
X
(H)Description of post developed conditions of the site
X
(I) Description of Detention Requirements for Development
X
(J)Description of Water Quality Requirements for Development
(K)Other
2
Calculations
All Reponses assume the new parish hall is the only "new" impervious surface
X
(A)Area Calculations
X
(B)Predeveloped Condition Runoff Curve Number
X
(C)Predeveloped Condition Time of Concentration
X
(D)Post Developed Condition Runoff Curve Number
X
(E)Post Developed Condition Time of Concentration
N/A
(G)Sub basin routing
X
(G)Predeveloped Condition Computer Model Results
X
(H)Post Developed Condition Computer Model Results
X
(I)Detention system assumptions
X
(J)Detention system routing computer model results
(K)Water Quality Storm Calculations
X
(L)Other
3
Plan View- Drainage Conveyance
X
(A)Label and clearly identify existing & proposed systems
X
Identify materials on sheet C4.0
(B)Identify slope, length, diameter & material for all pipes
Catch Basin size/type (check size based on depth, pipe size & angles)
(C)
X
X
(D)Catch Basin, invert elevations for all pipes
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Stormwater Management Review Checklist
Date:1/22/2010
(For New Developments with > 5,000 sq ft of new impervious surface
Site:Holy Rosary Church
or North Edmonds Earth Subsidence and Landslide Hazard Area )
Address:760 Aloha St
By: Jerry Shuster, P.E.
CompleteIncompleteComments
X
(E)Downspouts; provide connection (w/ adequate depth) to retention
X
(F)Pipe slope info versus inverts @CBs and existing pipe info
Describe any anticipated utily conflicts and show how they will be resolved based on current
X
information
(G)Profile storm system and show utility crossings
X
Show flow arrows on sheet C4.0 into and out of detention system
(H)Flow arrows as necessary
(I)Other
4
Plan View & Details- Retention/ Detention (R/D) & Water Quality
Uncoated CMP should not be used in this application. The shallow groundwater in this area
(evidenced by the extensive underdrian system proposed) necessities the use of alluminized steel
X
(A)Scaled drawing of R/D pond, vault or pipe, including tract boundaries
type 2, HDPE, or other material that will last in wet environment.
X
(B)Predeveloped & Finished Grade contours, show max water elev.
N/A
(C)Dimension all berm widths (Ponds only)
N/A
(D)Show 2 cross-sections through pond, 1 must show control structure
N/A
(E)Specify soils and compaction requirements for pond construction
N/A
(F)Location and detail of emergency overflow
N/A
(G)Rock protection details
Provide inverts of all pipes, grates, inlets, tanks, vaults & spot elev. of
(H)
X
Add invert out outlet pipe from control manhole
pond bottom
N/A
(I)Access road to control manhole and pond bottoms, plan & details
X
(J)Section and plan view of control structure
• The configuration of the 24 inch inlet and outlet pipes from the 72 in detention pipe does not
create any dead storage in the system. Re-configure to create dead storage in the detention tank
• Given the high grounwater, buoyancy tendencies must be balanced either by ballasting with
backfill or concrete backfill, providing concrete anchors, increasing
the total weight, or providing subsurface drains to permanently lower the groundwater table.
Calculations must be submitted that demonstrate stability.
X
(K)Other
Access risers need to placed every 50 feet on the detention pipes. Add one maintenance access to
X
(L)
each of the 72 inch detention pipes.
Maintenance plan
5
Plan View: Other
Show location, identification and dimensions of buildings, property lines,
(A)
X
streets, alleys & easements
Show locations of structures on abutting properties within 25 feet of
(B)
X
proposed project site.
Show section details of all retaining walls & rockeries, sections through
(C)
X
critical portions
(D)Other
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