To: Honorable Mayor and Members of Town Council
From: Mark Marlowe, Director of Castle Rock Water
David Van Dellen, Stormwater Manager
Title
Department Updates: Budget Request to Cherry Creek Basin Water Quality Authority on McMurdo Gulch Project
Body
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Executive Summary
The Town entered into a participation agreement with Cherry Creek Basin Water Quality Authority (Authority) in 2009 and again in 2011 for stream reclamation improvements for McMurdo Gulch. At that time, the Authority contributed a total of $630,000 or 42 percent of the total project budget of $1.5 million for the purposes of protecting water quality in the Cherry Creek watershed. The improvements spanned the length of approximately three miles of McMurdo Gulch and provided stream reclamation for targeted areas having shown early signs of instability due to upstream development. It was understood at that time that additional improvements would be required on McMurdo Gulch as the upper watershed continues to develop. These improvements are identified in the Town’s master plan for McMurdo Gulch.
Since the completion of the McMurdo Gulch improvements, the Authority has included McMurdo Gulch in the water quality sampling plan with monitoring sites upstream and downstream of the project reach. Over the past five years that the Authority has monitored nutrient concentrations at this location, it has consistently shown a 30 percent reduction in nutrient concentrations through the project reach. This data helps to support the benefit that stream stabilization provides to protecting water quality in the watershed and in Cherry Creek Reservoir, one of the main goals of the Authority.
The Town has identified stream reclamation improvements that are necessary over the next five years to address instabilities that have formed since the improvements were completed in 2012. The cost of these improvements are estimated to be $1.5 million over the next five years. The Authority provides for local agency members to present capital participation requests for projects that include a water quality benefit to the watershed. According to published information by the Authority, it is estimated that approximately 25 percent of the cost of stream stabilization measures can be justified for the purpose of pollution reduction facilities thereby providing the framework for budgeting the Authorities contribution. The Town is requesting a total participation from the Authority over the next five years in the amount of $379,000 to cover the cost of design and construction of stream reclamation on McMurdo Gulch. By way of reference, the Town’s residential customers contribute between $75,000 - $100,000 annually through property taxes and fees to the Authority. The average household in Castle Rock pays $13.50 annually in property taxes.
The previously completed improvements to McMurdo Gulch and the proposed next phase of work are shown on the attached map (Attachment A).
Should the Authority accept the capital budget with McMurdo Gulch included, the Town and the Authority will need to engage in a participation agreement. This agreement will come before Council for action prior to accepting any funding. There are no significant additional requirements for receiving funding towards this project from the Authority, and this project is part of Castle Rock Water’s long term stormwater capital plan.
Attachments
Attachment A: Map