Board of Adjustment Agenda and Packet 2016 12 21

Home Browse Search

Board of Adjustment Meeting Minutes November 16, 2016 Page 7 of 12 would not analyze the floodplain development permit. The next stop for that would be at building permit to verify the floodproofing methods and to comply with code. DeJong says it is my understanding that as far as our approval, it could be contingent upon subsequent analysis and approval of the floodproofing by the City. Zuccaro says yes, Staff thought it was an assumed condition, but it would not hurt to make it an explicit condition if you approve the proposal. DeJong says the BOA can approve it specifically contingent upon the floodproofing standards, the certification by a registered professional engineer or architect, and satisfaction of the floodproofing by the City and permits thereafter. Meseck says to speak to Allison's question, we have not heard a floodplain development permit recently. My understanding is that our scope is limited on those. We are simply determining whether we agree with Staff's recommendation that the impact to the floodplain is minimal or negligible. Gorsevski says we are operating under the assumption that some of these issues will be addressed such as the floodproofing of the building and that the process will adhere to the City's rules and regulations. Meseck says the primary reason for this is to insure we are not impacting other structures or parts of City property by this construction. Zuccaro says the general purpose and intent is to insure that the floodplain is not being impacted in any way to create an adverse impact up or down stream, and to make sure that the on-site development is appropriate, safe, and limits any potential property damage. Campbell asks about the map that has the blue and Tight blue. I am not familiar with the terms you used. Previously, I understood that floodplains were 100 year and 500 year. Zuccaro says the turquoise and the darker blue areas are the 100 year floodplain. There are two areas of the 100 year floodplain. The darker blue is called the floodway which is the water course and where the actual floodwaters would flow. The lighter blue is where water would build up but it is not flowing. I call it the backwaters. The 500 year floodplain is the orange and not part of the City's regulatioe 100 year floodplain falls under the City regulations. Applicant Presenta Ryan Byrne, Civil peer, PE, ,Martin/ , Inc., 12499 West Colfax Avenue, Lakewood, CO Joseph Lear, Davis Pa c i - - ake Street, #100, Denver, CO Byrne presents. We were tasked with preparin• e floodplain study for the floodplain development permit. Staff discussed the existing affected FEMA floodplain which was the aerial imagery. It is what FEMA currently recognizes as the affected floodplain and the analysis to support it was prepared by a consulting firm in 1996 before the Coal Creek development was built. In this map, the floodplain does not make sense with the topography and buildings that exist today. The subsequent Flood Hazard and Delineation (FHAD) study was done by RESPEC Consulting & Services in November 2014. The State and Urban Drainage has adopted that study as the regulatory study and the best information available. We have prepared both pre- and post -project conditions in support of the floodplain development permit, and it supports the no rise condition. The black line shown on the map is the FEMA effective line. The topography of the buildings presently there does not support the delineation and it is outdated. The addition is located in the 100 year floodplain as discussed. The floodway is the area reserved to convey the 100 year floodplain without causing an increase of a specified value. Anything more than 1/2 foot rise would trigger a Conditional Letter of Map Revision (CLOMR) process. In Section 17.56 regulations, any development within a floodway is prohibited 100% without causing no -rise. Those limits can be superseded or overridden if a CLOMR or Letter of Map Revision (LOMR) process has gone through and remapping is done. Typically, after a project is completed, a LOMR is completed and it remaps the floodplain. The comparison is between pre- and post -project conditions. It is not a comparison from the effected floodplain study that is currently viewed by FEMA as regulatory. The pre- and post -project