1997-06-13_REVISION - M1981302 (56)

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Page 7 mined site than in previously approved reclamation plans. These lower grades have created the potential to divert and redirect flood waters from South Boulder Creek to the north." Response: The land grades that the City of Boulder is concerned with are inside the existing berm. The currently accepted delineation of the one percent annual chance floodplain along South Boulder Creek excludes the land inside the levee from the floodplain. If the land inside the levee is not in the floodplain, there is no potential for the land grades inside the levee to affect flood flows resulting from a one percent annual chance flood. The exclusion of the land inside the levee from the floodplain has been called into question, due to the fact that the levee has not been certified by FEMA, and Federal Insurance Administration regulations provide for mapping areas behind levees as protected from the one percent annual chance flood only if the levee system has been certified. It is the Division's understanding that the landowner of the Deepe Farm Pit, which is now the University of Colorado, intends to have the levee certified by FEMA. Whether or not the levee is certified, the land grades behind the levee can be considered to have no influence on one percent annual chance flood flows. If the levee were to be removed or if it failed during a flood, it would be appropriate to analyze the effect of the proposed modified land grades that are a component of the amendment AM-002 application, as opposed to the currently approved land grades within the levee (as depicted on the 1989 amendment AM-001 map and on the 1991 technical revision TR-004 map). The 1989/1991 approved land grades within the perimeter levee include a chain of 4 groundwater and ditch-fed ponds with spillways and connecting channels. Since the ponds in the approved plan are designed to spill one into the next and ultimately drain off-site to the north, no flood water storage may be relied upon from the approved land grade and pond configuration. So, approving a different land grade and pond configuration could not adversely affect the flood storage potential of a reclaimed Deepe Farm Pit. Comment: "...the City of Boulder asks the DMG to refrain from approval of Western Mobile's proposed reclamation plan amendment for the Deepe Farm Pit until the Taggart study is complete and Western Mobile has had an opportunity (to) incorporate the results of the master planning effort into its final reclamation plan." Response: In accordance with Section 34-32.5-115, the Division must make a decision on an application for an amendment within a specifically defined time frame. The Division has no authority to delay the decision on the Deepe Farm Pit amendment application to await the results of the Taggart study. Moreover as explained above and below in the Division's reposes to comments under Issue 4, the change in the number of ponds from 5 to 2 has not significant flood implications.