With planning efforts “done,” officials are in the process of acquiring properties needed for the Upper Llagas Creek Flood Protection project before construction can start next year.
Staff from the Santa Clara Valley Water District recently updated the Morgan Hill City Council on the project that has been in the pre-planning stages since the 1950s. The nearly 14-mile long project will provide 100-year flood protection for properties from Buena Vista Avenue in Gilroy to just beyond Llagas Road in north Morgan Hill.
Despite the completion of key planning and design milestones, the SCVWD still has a lot of progress to make in acquiring funding. The total construction cost of the Upper Llagas Creek Flood Protection project is about $80 million, and the SCVWD has about $56 million.
“We’re a little bit short,” Steve Ferranti of SCVWD told the council Nov. 2, although they have enough money to complete the first of two phases next year. Funding comes from a variety of sources, including the U.S. Army Corps of Engineers, voter-approved property taxes, state agencies and local sources.
The project will require widening the existing creek in most sections as well as rechanneling it in others and tunneling through Nob Hill just west of downtown Morgan Hill, according to water district staff who spoke at the Nov. 2 council meeting. It will also revitalize wildlife habitat and provide recreational opportunities in some sections.
The project consists of a total of eight sections or “reaches” to be built in two phases, starting with the southernmost reach by next summer. At the same time that work is proceeding, crews will begin digging the tunnel out of Nob Hill, which is the site of a city water tank.
Ferranti said SCVWD will use earthen materials from the tunnel excavation for another project across town—the retrofitting of Anderson Dam off Cochrane Road. The dam has to be strengthened because state officials determined it is seismically unsound.
“We’re obviously trying to save money and utilize (the material) for both projects,” Ferranti said.
The downtown section of the project, known as “Reach 8,” includes the proposed Nob Hill tunnel and is one of the most complicated sections of the project, which will reroute Upper Llagas Creek’s flood waters through underground culverts and through the tunnel, according to SCVWD staff.
This reach is part of “phase two” construction. Officials expect to begin seeking a construction contract for this phase by November 2017.
SCVWD, the project sponsor, still needs dozens of private properties along the project route in order to begin construction on phase one, Ferranti told the council. Of the 149 properties needed, 82 owners have accepted offers from the SCVWD.
Restoration will provide habitat, recreation
Another unique aspect of the project is the proposed restoration of Silveira Lake, which is off the west side of Monterey Road just south of Morgan Hill. This part of the project will be completed with phase one construction.
The lake’s restoration will improve habitat for migratory steelhead trout and provide permanent wetlands for other wildlife, SCVWD Fisheries Biologist Melissa Moore told the council. This includes islands within the lake to protect bird species from feral cats and other non-native mammals that inhabit the area.
The project will also remove about 70 acres of Himalayan blackberries, an invasive species that has grown unchecked along the creek for several years. This vegetation will be replaced with “native understory,” Moore said.
The Silveira Lake design, which is “100 percent” complete, will also incorporate recreational facilities for humans, including new trails and benches.
“I think it will be a very positive community attribute,” Moore said. “Aesthetically, I think it’s going to be quite lovely.”
Morgan Hill officials have been lobbying for completion of the Upper Llagas Creek project ever since it was proposed in 1954. When complete, it will prevent flooding in Morgan Hill during torrential storms, particularly in the downtown where past floods have damaged businesses and residences.
Upper Llagas Creek has seen major flooding during 14 major storms since 1955, including most recently in 2008, 2009 and 2011, according to SCVWD staff.
