The proposed project addresses priority improvements identified in the City's 2015 Master Water Plan. The City's water supply is provided through the diversion of a few of the 16 springs that are collectively known as Mossbrae Springs (Springs). The proposed project is necessary for continued use of the Springs as the City's water supply, and for the general health and well-being of City residents.
Proposed improvements at Mossbrae Springs include the following: removal and replacement of the existing parallel 12-inch steel water pipes with a single 18-inch steel pipe; installation of isolation valves, sample taps, and overflow lines to the existing drainage for each spring; demolition and replacement of five existing concrete spring boxes with new concrete spring boxes and sanitary sealed access hatches to improve security of the spring resources from vandalism and contamination; replacement of the steel doors on Tunnel 1 and 2 of Spring 2; demolition and replacement of the weir building with a concrete retaining wall and a vault containing flowmeters and piping to maintain the existing hydraulics; replacement of existing culverts; installation of a new drain box adjacent to the vault; installation of Supervisory Control and Data Acquisition (SCADA) systems on the existing emergency chlorination facility and the new overflow and diversion flow meters; addition of 4-inch thick gravel fill along the access pathway; and updates to the existing SCADA system at the North Dunsmuir Tank including replacement of the existing antenna and modifications to the existing control panel.
Additionally, the project includes a new, permanent emergency chlorination system located at the Castle Rock Water Bottling facility. An existing vault would be demolished and replaced by a new chlorine injection vault, a chlorine building would be constructed to the west of the bottling facility, and a new 4-inch waterline would connect the two structures. The new chlorination system would be connected to the existing waterline extending from the springs to North Dunsmuir. The chlorination facility would be used on an as-needed basis.