From the US Army Corps of Engineers:
The U.S. Army Corps of Engineers Sacramento District has posted Public Notice SPK-2021-00088 to www.spk.usace.army.mil/Media/RegulatoryPublicNotices.aspx
The Contra Costa Water District has applied for a permit discharge dredged or fill material and work in approximately 1842.28 acres of waters of the United States, to modify the existing dam and reservoir and increase the reservoir storage capacity to 275 thousand acre feet (TAF) with necessary infrastructure. The approximately 1842.28-acre project site is located the Los Vaqueros Watershed, Latitude 37.849275°, Longitude -121.691823°, Brentwood, Contra Costa County, California, and can be seen on the Byron Hot Springs USGS Topographic Quadrangle.
Written comments and/or a request for a paper copy of the notice may be submitted to project manager Erin Campbell by email at Erin.M.Campbell@usace.army.mil, or telephone 916-557-5263.
Comments must be received by July 15, 2021.
