BOARD AGENDA MEMORANDUM
SUBJECT:
Title
Update of the Condition of the Coyote Percolation Dam (San Jose) (District 1) and Determination that the Condition of the Coyote Percolation Dam Continues to Constitute an Emergency.
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RECOMMENDATION:
Recommendation
Determine by a four-fifths vote that there is a need to continue the emergency action declared by the Board on August 22, 2017, pursuant to California Public Contract Code ?22050, to repair the Coyote Percolation Dam.
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SUMMARY:
On August 22, 2017, the Board declared that the condition of the Coyote Percolation Dam constituted an emergency condition pursuant to California Public Contract Code ?22050, and that District staff may repair such dam, take any directly related and immediate action required by that emergency, and procure the necessary equipment, services, and supplies for those purposes, without giving notice for bids to let contracts. The emergency condition continues to exist as the repairs to the Coyote Percolation Dam have not been completed.
The Coyote Percolation Dam (dam) is an in-channel dam located on Coyote Creek. Under normal operation, steel panels are secured to the concrete foundation; a concrete apron protects the downstream side of the dam. A concrete fish ladder allows fish migration when the dam is in place. A set of radial gates allows flow releases to manage the impoundment behind the dam. The dam is regulated by Division of the Safety of Dams (DSOD) and is inspected regularly for condition and operational safety.
The storm flows on February 21-22, 2017, damaged the dam facility severely, in particular the dam apron suffered a scour hole that may have extended below the foundation. The exact extent of the damage was unknown because visibility was restricted by the concrete apron and the material beneath the apron.
Under an emergency permit issued by the Army Corps of Engineers,
(File No. 2017-00166S/NWP 5, issued March 17, 2017), actions were taken to temporaril...
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