Fremont Weir Adult Fish Passage Modification (Lake and Streambed Alteration Agreement No. 1600-2017-0067-R2)

Fremont Weir Adult Fish Passage Modification (Lake and Streambed Alteration Agreement No. 1600-2017-0067-R2)

CDFW has executed Lake and Streambed Alteration Agreement No. 1600-2017-0067-R2, pursuant to section 1602 of the Fish and Game Code to the project Applicant, DWR. Project is limited to the following activities: 1) Installation of sheet piling for erosion control on the river side of the weir. 2) Replacement of the existing fish passage structure through the Fremont Weir. This includes removal of the existing structure, widening the slot in the weir to install the new structure, deepening of the invert for the structure, installation of the new structure, and installation of a water flow control gate for the structure, and installation of an elevated platform with control panel for operation of the gate structure. 3) Enhancement and recontouring of the escapement channel from the weir to the Sacramento River. This includes widening of the existing channel, deepening of the existing channel, re-sloping the sides of the existing channel, placement of an engineered rounded streambed material on the bed of the channel and placement of angular rock slope protection on the banks of the channel above the Ordinary High Water Mark (OHWM). 4) Creation of an approach channel to the Bypass side of the fish passage structure from the Deep Pond. This includes creating a channel from the deep Pond to the landward side of the fish passage structure, sloping of the banks of the channel, placement of rounded engineered streambed material on the bed of the channel, and placement of angular rock slope protection on the banks of the channel above the OHWM. 5) Creation of a vehicle access maintenance road on both the landward and river sides of the weir. 6) Transport for offsite disposal all soil construction spoils utilizing existing vehicle access and farm roads. 7) Removal of "Agricultural Road Crossing 3" on the Tule Canal. The project consists of the permanent removal of all culverts and a compacted soil roadway created to allow vehicular and farm equipment access across the Tule Canal. This project will include temporary impacts to approx. 0.17 acres of grasslands and permanent impacts to approx. 0.01 acres of riparian habitat and 0.03 acres of grassland within the actual crossing as well as the adjacent staging area. If water is present prior to the start of removal activities, a temporary cofferdam will be constructed an water drained from the site. 8) Removal and replacement of "Agricultural Road Crossing 2" on the Tule Canal. The project consists of the removal of the existing agricultural vehicle crossing of the Tule Canal and replacement of the crossing with a new concrete culvert crossing. The canal bed will be trenched to a depth of 5 feet and approx. 530 tons of aggregate base placed within a trenched area in the canal. Six 26 foot wide by thirteen feet high by eighteen feet wide precast concrete culverts will be placed on this aggregate base. Following installation of the culverts approx. 2,200 cubic yards of engineered streambed material (ESM) will be placed in the bottom of the culverts. Concrete wing walls will be installed on both the upstream and downstream sides of the crossing to minimize the risk of bank erosion from high stormwater flows in the canal. A concrete crossing with removable guardrails will be installed on top of the culverts to allow for agricultural vehicular access to fields on either side of the canal. If water is present prior to the start of removal activities, temporary cofferdams will be constructed and water drained from the site. 9) Removal and replacement of existing irrigation water diversion pipe in Tule Canal at "Agricultural Road Crossing 2". The existing water diversion pipe and valve will be removed as part of the grading and removal of Ag Crossing 2. A new diversion pipe and flashboard riser gate will be installed at the same time as the Ag Crossing 2 culverts are installed.

Davis, West Sacramento

Yolo