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<br /> <br /> Employee Owned <br /> <br /> <br />2480 W. 26th Street, Unit B225 <br />Denver, Colorado 80211 Tel: +1 303-964-3333 hello@merrick.com <br />www.merrick.com <br /> <br />January 18, 2019 <br /> <br />Mr. Brad Dallam, PE <br />City of Lafayette <br />1290 S. Public Road <br />Lafayette, Colorado 80026 <br />RE: Goosehaven Reservoir Complex, Expansion Project – Cell-2A, Hydrology Report <br />Dear Brad: <br />Attached please find a hydrology report for the Goosehaven Reservoir Complex, Cell 2A. The project is located <br />just south of Boulder Creek, west of Highway 285. This report was prepared to support design for the addition of <br />Cell 2A. <br />The report describes site hydrology and it describes two significant features of the planned improvements. First, <br />an interceptor swale will be constructed upstream of the reservoir complex. The swale will intercept all overland <br />runoff up to and including the 100-year event from upstream basins and divert the runoff from the reservoirs. <br />Therefore, there will be no additional inflow from upstream during rainfall events, which simplifies the reservoir <br />operations and any safety concerns. <br />Secondly, the design includes 3.5’ of freeboard from the normal pool to the reservoir embankment. This <br />freeboard is more than sufficient to contain the 100-year 24-hour rainfall of 5.1 inches. The reservoir site meets <br />the State’s criteria for a low hazard dam, and the State requires that the facility can handle an event of this <br />magnitude for the low hazard classification. <br />Furthermore, this report shows dam break calculations to support the low hazard classification. All calculations <br />and support for the hydrology above are found in the report appendices. <br />Thank you for the opportunity to assist you. If you have any questions, please contact Brian Chevalier at <br />303-800-9048. <br /> <br />Sincerely, <br />MERRICK & COMPANY <br /> <br />Brian Chevalier, PE, PMP Magdiel Garcia, EI <br />Project Manager Design Engineer <br />cc: File <br /> <br />EXHIBIT E Attachment-B page 2 of 35