HomeMy WebLinkAboutMemo - Mail Packet - 5/7/2019 - Memorandum From Theresa Connor Re: Boxelder Watershed B-2 And B-3 DamsUtilities
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PO Box 580
Fort Collins, CO 80522
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utilities@fcgov.com
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M E M O R A N D U M
DATE: April 18, 2019
TO: Mayor Troxell and Councilmembers
FROM: Theresa Connor, P.E., Utilities Deputy Director, Water Engineering & Field
Services
THROUGH: Darin Atteberry, City Manager
Jeff Mihelich, Deputy City Manager
Mike Beckstead, Chief Financial Officer
Kevin R. Gertig, Utilities Executive Director
RE: Boxelder Watershed B-2 and B-3 Dams
Bottom Line:
The State Engineer’s Office has upgraded the hazard classification of two flood control dams in
the upper Boxelder Watershed (B-2 and B-3 dams) due to land use changes from agricultural use
to urban/suburban land use in the downstream watershed. Improvements are needed to the dam
spillways as they are inadequately sized to pass major flood events to maintain their certification
for flood protection purposes. A stakeholder group of Larimer County, Cities of Wellington,
Timnath, Windsor and Fort Collins, and the North Poudre Irrigation Company (NPIC) has been
formed to develop an Inter-Governmental Agreement (IGA) to form a plan to complete the
needed capital improvements and on-going maintenance needs. The first phase of this IGA
would come to Council this summer. The second phase of the IGA in spring 2020, and a budget
offer is expected in the 2021/2022 BFO cycle to address Fort Collins Utilities share of these
improvements.
Background:
A series of flood control dams were built in the 1970s and 1980s to protect agricultural lands
from flooding and erosion damage. At the time, the North Poudre Irrigation Company (NPIC)
acted as the local partner with the Soil Conservation Service (SCS) now the Natural Resources
Conservation Service (NRCS) with the United States Department of Agricultural (USDA) to
build the dams. NPIC currently operates and maintains the dams. In 2014, the State Engineer’s
Office completed a routine review of the dams for certification. In their review, they indicated
that the land-use change downstream of these dams from agricultural use to suburban/urban
development required a change in the dam classification from “moderate” to “high hazard”. This
change in classification of the dams requires improvements to the emergency spillways of the
dams. The NPIC has indicated they cannot complete these improvements and that they are not a
flood protection agency, so they are looking for the local governments who do provide flood
DocuSign Envelope ID: EEA67643-F08C-42A9-83DB-5316C1040574
protection services to their communities to take responsibility for the dams. Upgrades to these
dams to meet appropriate classifications is important to the downstream communities to protect
their investment for flood protection projects in the Boxelder Basin. If these dams were to be
decertified because of a lack of hazard rating; the change to the floodplain downstream would be
significant. This change in floodplain would impact over 1,000 residences and businesses in
Larimer County, Wellington, Timnath, Fort Collins, and Windsor.
The NRCS has a program for cost share to make these improvements. Federal funding of up to
65% of the costs of the improvements may be available if a local government agency will act as
the local sponsor (35%) and maintenance provider. Larimer County has indicated that they will
act as the local sponsor along with NPIC. The stakeholder group is actively working through the
issues associated with these dams to bring forward solutions and make the safety upgrades
needed. The dams are located outside of the geographical jurisdiction for the Boxelder Basin
Regional Stormwater Authority and therefore not within the BBRSA’s authority to administer
the project.
CC: Ken Sampley, P.E., Director Stormwater Engineering & Development Review
Eric Potyondy, Assistant City Attorney
DocuSign Envelope ID: EEA67643-F08C-42A9-83DB-5316C1040574