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 <preek Hydrologic Study

6.2 Wright Property

As shown in Appendix A, Photographs 22 tllrough 28, the primary concern is the steep cut bank
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and accelerated erosion threatening the Wright's irrigation ditch. This concern was initially
raised by Barry Marrs, who previously farmek this property. Stabilization of the streambank and
realignment of the ditch are needed to contro~ this problem.

6.3 Chikuma Property

As shown in Appendix A, Photographs 30 through 44, the primary problem on the Chikuma
property is erosion and overtopping of the diveway bridge leading to the house. An oil and gas
company provided two large culverts several years ago, but erosion is occurring around these
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culverts and overtopping occurs. A potential solution would be a low water crossing comprised
of reinforced concrete box culverts engineerld to pass frequent flows and an armored drive: that
would act as a weir for larger events, passinJ flows without washing out the road. Mr. Chikuma
reported that he has begun parking his car oh the upstream side of the creek when storm events
occur so that he is able to get out if needed.

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An oiVgas tank with containment berm is located relatively near the creek and pipelines run
parallel to the creek across Mr. Chikuma's p~operty.

6.4 Rosenbrock Property

For the last several years, the Rosenbrocks have repeatedly raised concerns about high water and
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driveway flooding near their home. Appendix A, photographs 46 through 53 show the driveway

bridge that is overtopped during high flow chnditions. The Rosenbrocks stated that overtopping
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has occurred with increased frequency over the last 10 years.

6.5 Wagner Property

Gary Skelton showed WWE around the Wagner property (Appendix A, Photographs 54 through
57), which contains several hairpin-like meJuders experiencing accelerated erosion near County
Road 21. This property had some concretd blocks on the banks that have become covered in
vegetation. The property inside of one ben~ is completely denuded, but appeared to be a good
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Wright Water Engineers, Inc.

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971-179.092
June 2005

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