HomeMy WebLinkAboutENCLAVE AT REDWOOD - FDP220014 - DOCUMENT MARKUPS - ROUND 2 - STORMWATER-RELATED DOCUMENTSBegin SWMM Modeling Comments.
FOR FINAL APPROVAL:
Modeling A2 Line - Please confirm if the SWMM model was updated to reflect the as-designed elevations and lengths of the proposed A2 line. If not, please make these updates.
The A2 Line has been updated in the Proposed SWMM Model.
FOR FINAL APPROVAL:
Modeling A3 line Comments:
Add the A3 line to the SWMM model and add detail to the model for each A3 line manhole and each pipe (from Redwood East to Necco main).
The A3 Line has been added to the proposed SWMM Model.
Adjust the SWMM model to reflect proposed hydrologic conditions for the A3. See attached images for more information.
The A3 Line hydrology has been updated in the Proposed SWMM Model.
Update the hydraulics and confirm sizing of the A3
The A3 Line hydraulics has been updated in the Proposed SWMM Model.
FOR FINAL APPROVAL:
The subbasin naming convention needs to be cleaned up for clarity. Do not change the original numbering of the subbasins (such as 113_2), however adding suffix or prefixes is fine.
See included image for more information. I think this is a repeat comment from PDP.
The subbasin naming convention has been cleaned up. Basin names are closer to what they were in the model we received from the City of Fort Collins. Suffixes have been added to denote
subbasins that were previously part of a larger basin.
FOR FINAL APPROVAL:
The proposed condition SWMM model appears to be missing approx. 1.3 acres from the existing condition model. The total area should not be changing in the hydrology model. Please review
and revise or explain.
The SWMM Model areas have been balanced with the known survey areas. All changes to the provided model have been documented in the form of Existing Conditions, revised Existing Conditions,
and proposed basin maps, provided in the drainage report.
FOR FINAL APPROVAL:
The SWMM imperviousness values appear low. For the FDP model you will need to perform provide direct imperviousness calculations from plans for each SWMM subbasin. Include documentation
in the drainage report showing the imperviousness calculations.
The SWMM imperviousness values have been updated.
FOR FINAL APPROVAL:
Pond Modeling Comments:
**The peak allowable detention release rates appear to be calculated incorrectly. The maximum release rate is 0.2 cfs/acre in this watershed. This should be calculated on a pond-by-pond
basis. Please review your design and update the SWMM modeling and pond sizing.
The peak detention release rates have been met in the proposed model.
The detention pond outlets are modeled incorrectly. For PDP it was allowed to simply model pond outlets as conduits with a max flow value set. However, for final models the detention
outlets need to be modeled using an accurate rating curve or physical SWMM orifice or weir set in the model. The pond outlets need to be revised to match the design.
The detention pond outlet modelling has been cleaned up
Pond 3 has a max depth set that is lower than the rating curve depth
Pond 3 (Park Pond) max depth issues have been resolved.