Tree Removal in Kirk Diversion Dam Vegetation Management Area

Located in Los Gatos Creek County Park in the town of Los Gatos, the Kirk Diversion is an instream facility on Los Gatos Creek used for diversion, re-diversion, and conveyance of water to groundwater percolation ponds in the Los Gatos Groundwater Recharge System. Kirk Diversion Dam is comprised of an inflatable rubber dam installed on top of a concrete apron. The inflatable dam is 90 feet long and spans the concrete apron. Kirk Diversion Dam may be inflated or deflated at any time to divert or redivert local flows, and will automatically deflate for unanticipated high flows when the depth of water is 1.4 feet above the dam crest. A sluice gate at the east side of the dam is used to bypass up to 250 cubic feet per second (cfs) through a low flow channel. The Kirk Diversion Dam Vegetation Management Area extends 100 feet downstream of the Kirk inflatable dam and concrete apron. Valley Water proposes to remove approximately 30 live standing, live fallen, dead/dying standing, and dead fallen native, non-native, and invasive trees from the Kirk Diversion Dam Vegetation Management Area to re-establish the clear zone below the dam; prevent damage to the inflatable dam from fallen trees, provide access to the area below the dam for maintenance; prevent flow obstructions and alteration of flow patterns in the low-flow channel downstream of the dam; and allow for visual inspection and camera surveillance of the inflatable dam and it’s appurtenances from downstream areas. Equipment would enter the Los Gatos Creek channel below Kirk Diversion Dam from the right bank. A temporary access ramp over the low flow channel would provide equipment access to the left bank. Depending on groundwater conditions during construction, temporary sump pumps and hoses may be used to maintain a dry work area on either side of the low flow channel. Water pumped out of the work area would be released back to Los Gatos Creek approximately 20 feet downstream of the Kirk Dam Vegetation Management Area. Trees would be removed using traditional climbing techniques. Valley Water Standard Best Management Practices (BMPs) and Santa Clara Valley Habitat Plan Aquatic Avoidance and Minimization Measures (Aquatic AMMs) have been incorporated into the project. The BMPs and Aquatic AMMs would protect riparian and aquatic habitat and prevent sedimentation and degradation of water quality in Los Gatos Creek. The project is anticipated to take 3 weeks to complete.