FLOOD01745

• Designation Number: 510
• County: Adams
• Community: Northglenn
• Title: Flood Insurance Rate Map - Northglenn, Adams County Colorado
• Date: 3/1/1981
• Designation Date: 1/1/2000
• Floodplain - Doc Type: Correspondence

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Resolution No. 354.14, except for the stream reach where floodplain revisions were drafted for
South Fork Grange Hall Creek as previously described; and '

WHEREAS, the approximate floodplain delineations contained on said map dated March
31, 1981 for flooding sources as listed in Table 3 are consistent with the floodplain delineations
contained in Resolution No. 354.14 (Table I, Ref. No, 1); and

WHEREAS, the detailed floodplain information for South Fork Grange Hall Creek in the,
vicinity ofInterstate 25, contained in existing floodplain studies for the City of Northglenn Cfable
I, Ref. Nos. I through 5), is not consistent with a proposed Letter of Map Revision (LOMR), not
yet approved by FEMA, that would revise said detailed floodplain information due to construction
of a new culvert under Interstate 25; and

C.RS. AUTHORITY
WHEREAS, Section 37-60-J06(1)(c), Colorado Revised Statutes, requires the Colorado
Water Conservation Board to assist in the prevention of floods and flood damages therefrom; and

WHEREAS, Sections 31-23-301 and 30-28-111, Colorado Revised Statutes, provide that
legislative bodies of local jurisdictions may provide zoning regulations for land uses on or along
any storm or floodwater runoff channel or basin only after designation and approval by the
Colorado Water Conservation Board; and

WHEREAS, Section 37-60-J06(l)(c), Colorado Revised Statutes, directs the Colorado
Water Conservation Board to designate and approve storm or floodwater runoff channels or basins
and to make such designations available to legislative bodies of local jurisdictions; and

COMPLIANCE WITH CWCB TECHNICAL STANDARDS
WHEREAS, the detailed hydrology information for the streams listed in Table 2 in
Resolution No. 354.14 is consistent with the requirements for detailed hydrology information listed
under the Board's "Rules and Regulations for the Oesignation and Approval of Floodplains and of
Storm or Floodwater Runoff Channels in Colorado" (2 CCR 408-1); and

WHEREAS, a procedure for determining hydrology information in the City of North glenn
for the approximate floodplains as listed in Table 3 has not been established by the CWCB; and
those floodplain areas may not be designated as approximate floodplain information without a
procedure for estimating 100-year peak flows, and therefore the local government should require
that a detailed hydrologic and hydraulic study be perfOrmed by a professional engineer and
submitted by the developer or the development proponent prior to any floodplain development in
those cases; and

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