HomeMy WebLinkAboutSYMBIOS LOGIC PUD - FINAL - 5-94F - SUBMITTAL DOCUMENTS - ROUND 1 - RESPONSE TO STAFF REVIEW COMMENTS•
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:13DINC.
Engineering Consultants
A division of The Sear -Brown Group
TO:
Matthew Fater - Stormwater Dept.
FROM:
Patricia Kroetch
SUBJECT:
Symbios Logic Comment Responses
DATE:
June 24, 1996
MEMORANDUM
Our responses to your comments on the preliminary submittal are as follows:
A SWMM model was used to size the interim detention pond #1 for the Phase I conditions.
It is included in the appendix.
2. Proposed contours for Phase I are shown on the drainage plan. The length used to determine
tributary width for sub -basin 31 is an average embedded conveyance element length. This is
consistent with SWMM modeling practice as shown in Figure 4-13 of the SWMM Version
4 User's Manual. As an aside, the unit discharge from this basin appears to be consistent with
unit discharge from commercial properties along the Front Range.
Topography of off -site basins was obtained from the Fox Meadows Mater Drainage Study
and/or City of Fort Collins aerial photography. Runoff from the upstream off -site basin is
consistent with master plan conditions.
4. This has been addressed in the text of the drainage report.
We are coordinating with Stewart & Associates, Inc. to accomplish this.
6. This is included in the revised drainage report.
7. As only a portion (approximately one-third) of Pond 215 is to be constructed with Phase I,
the interim Pond 215 and downstream outfall facilities are modeled using conventional culvert
analysis. Dynamic hydraulic analysis will be completed when the multi -part detention pond
goes to final design.
8. For the overall drainage study, upstream off -site development must conform to an allowable
release of 0.3 cfs/acre due to existing downstream constrictions and master plan requirements.
During the interim condition, the full historic runoff from the upstream property will be routed
through the interim on -site detention pond.