[BoulderCouncilHotline] Staff's understanding of council direction for South Boulder Creek flood mitigation design

[Scarbrough, Molly]

Good morning council members -

In response to questions raised at CAC on Monday, below is staff's understanding of the direction provided by council on Aug. 21 regarding next steps in the South Boulder Creek flood mitigation design process:


  *   Council voted 6-3 to direct staff to proceed with the next steps of preliminary design and landowner negotiations for the Variant 1 500 year concept (without CU levee), and, within that concept, evaluate ways to minimize flood detention on the Public (PUB) land use on CU South. Council directed staff to explore combining Variant 1 500 with upstream storage to see if that would reduce the impact on the PUB land use.
  *   In addition, council provided the following direction for studying upstream storage:
     *   Work with existing topography - do not include a berm or rundown structure [to channel water into the upstream area - thereby avoiding those direct impacts to sensitive habitats]
     *   Avoid placing permanent structures on OSMP land
     *   Eliminate the need for a flow control structure
  *   Council acknowledged that:
     *   The design could potentially reduce inundation on OSMP land
     *   The design would not eliminate the need for a groundwater conveyance system
  *   Council also asked staff to:
     *   Evaluate whether oversizing the outlet pipe could help make the concept more adaptable for climate change
  *   Council asked staff to return on Sept. 20 to discuss next steps for the annexation process and to show an illustration of a modified Variant 1 500 year concept that could meet the direction provided by council on Aug. 21.
  *   Council stated their intent to continue to work with the University of Colorado.

Please contact me if you have any questions.

Thanks,

Molly Scarbrough
Senior Project Manager
[https://bouldercolorado.gov/links/fetch/32017]
O: 303-441-4939
scarbroughm at bouldercolorado.gov<mailto:scarbroughm at bouldercolorado.gov>

Department of Public Works
1739 Broadway | PO Box 791 | Boulder, CO 80306
Bouldercolorado.gov<https://www.bouldercolorado.gov/>

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