FLOOD10420

• County: Adams
• County: Broomfield
• County: Weld
• Community: Broomfield, Westminster and Thornton
• Stream Name: Lower Big Dry Creek
• Title: Lower Big Dry Creek Hydrology Study
• Date: 6/1/2005
• Prepared For: Big Dry Creek Watershed Association
• Prepared By: Wright Water Engineers, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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Lower Big Dry Creek Hydrologic Study

a brainstorming meeting with upstream stormwater managers, conducted a limited literature
review of approaches used in other areas, reviewed previous studies completed in the watershed,
reviewed current stomlwater management policies and plans in place in the watershed and
analyzed available hydrologic data. Based on the findings of these activities, WWE has proposed
and evaluated various approaches to improve conditions in the lower watershed and made
recommendations for future strategies for stormwater management.

As an engineering firm, WWE has provided scientific answers (within the limits of the available
data) to the questions asked; however, it should be noted that the issues in the Big Dry Creek
watershed go beyond the realm of science into social, economic, legal and political arenas.
WWE has limited its analysis to the scientific and engineering issues. Information presented in
this report is suitable f,~r planning and prioritization purposes, but should not be used as a basis
for engineering design without further refinement.

2.0 BACKGROUND ON THE BIG DRY CREEK WATERSHED ASSOCIATION

This study is sponsore:d by the Big Dry Creek Watershed Association (BDCW A), which was
formed under an intergovernmental agreement in 1997 and formalized as a non-profit
corporation in 2004. The Board of Directors includes representatives of the cities of Broomfield,
Westminster, Northglenn and Thornton and Weld County. Public meetings are held quarterly
with a larger group of stakeholders to address watershed issues. The mission of the BDCW A is
to develop a sound scientific understanding of water quality, flow, aquatic life, and habitat
conditions in the Big Dry Creek watershed for the purposes of 1) environmentally responsible
decision-making with regard to land and stream uses and 2) identifying measures to improve and
protect stream conditions. The goals of the BDCW A include three broad categories: 1) public
education and involvement, 2) monitoring and study, and 3) protecting, preserving and restoring
water quality, aquatic life, and habitat. While the BDCW A has no regulatory or legal authority
with regard to local governments in the watershed, the BDCW A voluntarily works to improve
conditions in the watershed and serves as a technical resource for the communities and
individuals in the watershed. In keeping with these goals, the priorities identified in the Big Dry
Creek Watershed Management Plan (WWE 2002), and concerns of it stakeholders, the BDCW A
pursued and obtained funding for this hydrologic study.
971-179.092 Wright Water Engineers, Inc. Page 11
June 2005