COMMITTEE AGENDA MEMORANDUM
Agricultural Water Advisory Committee
Government Code § 84308 Applies: Yes ☐ No ☒
(If “YES” Complete Attachment A - Gov. Code § 84308)
SUBJECT: title
Receive an Update on the Upper Llagas Flood Protection Project.
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RECOMMENDATION: Recommendation
Receive project information on the Upper Llagas Flood Protection Project and the current construction status.
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SUMMARY:
Valley Water is currently constructing the last phase of the Upper Llagas Creek Flood Protection Project (Project). This project which started way back in 1968 as a partnership with the State of California, and then later in 1999, as a partnership with the U.S. Army Corps of Engineers (USACE) and the City of Morgan Hill (City) to provide 1% flood protection to more than 1,100 residences and 500 businesses along West Little Llagas Creek, East Little Llagas Creek, and Llagas Creek. The Project, part of the renewed Safe, Clean Water and Natural Flood Protection Program, is approximately 13.9 miles long and is located within the cities of Morgan Hill and Gilroy, and various unincorporated areas of Santa Clara County, including San Martin.
Llagas Creek and its tributaries are part of the Uvas/Llagas Watershed, the area of land over which rain falls and then drains southward to the Pacific Ocean through Monterey County or into reservoirs for storage. The Uvas-Llagas Watershed is a 104-square-mile region that is distinguished by its agricultural lands, open space, and natural areas. Part of the larger Pajaro River Watershed, the creeks within this watershed are the only waterways in Santa Clara County that flow southward.
The Project consists of channel widening and deepening, instream improvements for wildlife and habitat, constructing box culverts, underground high flow bypass tunnel, and revegetation. The Project’s mitigation elements to offset environmental impacts associated with the construction work include the following environmental elements:
• Riparian mitigation consisting of approximately 114 acres of native vegetation plantings;
• Creation of the Lake Silveira wetlands, approximately 5 acres;
• Creation of plant, fish, and wildlife habitat;
• Invasive plant removal (13.0± acres);
• In-stream complexities-woody debris (464 instream complexity features including divide logs, wing deflectors, root wads and boulder clusters);
• Turtle basking sites within the created wetlands (10 turtle basking sites);
• Tree girdling (27 invasive trees girdled for bat/owl habitat);
• Bat boxes (14);
• Upland log piles (148 locations);
• Removal of legacy trash & hardscape debris (2.3± acres of remediation); and
• In-fill native planting sites (11± acres).
The Project is being constructed in three phases (Phases 1, 2A, and 2B) and intended flood protection will only be realized after construction is completed for all of them. Staff presentation (Attachment 1) at the committee meeting will give an overview and status update of the project.
ENVIRONMENTAL JUSTICE IMPACT:
There are no Environmental Justice impacts associated with this item.
ATTACHMENTS:
Attachment 1: PowerPoint
UNCLASSIFIED MANAGER:
Manager
Bhavani Yerrapotu, 408-630-2735