[BoulderCouncilHotline] Additional follow-up questions on Hogan Pancost

[Young, Mary]

Dear Staff,


Below are additional questions with respect to 10/10/2017 Hogan Pancost public hearing related to flood maps, flood detention and design, and rights of way.


1. What were the initial condition assumptions in the flood models that were used to develop the 100-yr and 500-yr maps? Would the maps look different if there were several days of rain prior to the modeled event? Could that explain the difference between the observed flooding and the predicted flooding?


2. In annexation review, is there any constraint on basing decisions on observed, historical flooding instead of modeled flooding? In other words, which carries more weight, observed flooding or modeled flooding?


3. What frequency (type) of event is the applicant required to design site plan drainage and detention to, e.g. 5 yr, 10 yr, 20 yr storm? Of what duration is the design storm?


4. When asked about water table depth and detention pond design, applicant stated that because of high water table, detention would require a berm. What height might the berm be expected to be? Following berm design, what additional analysis would be required to determine the impacts of the berm itself on the surrounding area?


5. Applicant stated that storm water would be routed off of the site. How would this be done without affecting wetland quality? Would routing design differ on jurisdictional vs. non-jurisdictional wetland?


6. If the density calculation were to include ROWs (Rights of Way) who would own and maintain the sidewalks and tree lawns?


Thank you,


Mary Dolores Young

Boulder City Council

303-501-2439
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