Two meetings to discuss the Small Communities Flood Risk Reduction Feasibility Studies will be held next week in the communities of Princeton and Colusa.
The Princeton meeting will be held at 6:30 PM on Tuesday, Dec. 10, at Princeton High School. The Colusa meeting will be held at 6:30 PM, on Thursday, Dec. 12, at Egling Middle School.
Joe Thomas, chief engineer on the flood risk studies, said he hopes to glean from these meetings how these small communities should best proceed with improving the Sacramento River levees in order to meet FEMA’s new 100-year flood protection criteria.
Thomas is with Kjeldsen Sinnock Neudeck, the civil engineering firm tasked this past year with the doing the geological and hydraulic studies that have determined that serious deficiencies do exist in the levees.
“The first thing we did was seek to find the conditions the levees are now in,” Thomas said, at a Nov. 21 joint meeting of the Colusa County Board of Supervisors, City of Colusa, and Westside Levee District. “We did that through a variety of different means.”
In Princeton, over 8,600 feet of levee is in need of improvement to reduce the risk of a catastrophic flood.
The needed improvements, estimated to cost about $21 million, include constructing seepage berms and seepage cut off walls, along with rock slope protection against erosion.
Eight residences, as well as Princeton High School and Princeton Wastewater Treatment Plant, which would still be considered high risk if a levee breach occurred upstream or downstream, would need to be elevated or flood-proofed, officials said.
In Colusa, over 29,000 feet of Sacramento River levee needs to be improved to meet FEMA’s 100-year protection criteria.
Like the levee that protects Princeton, the needed improvements along the river in Colusa include seepage berms and seepage cut off walls, along with rock slope protection against erosion.
In addition to the flood risk from the Sacramento River, the Colusa Basin Drain is also a potential danger to Colusa. The existing Powell Slough levee needs remediation, and a new levee along Powell Slough is needed south of Highway 20, officials said.
The total cost for the Colusa improvements is estimated at $198 million.
Thomas said the public meetings are to discuss the pros and cons of the recommendations for remediation.
Colusa officials said the California Department of Water Resources has about $29 million available for Phase 2 in the process, but that a local cost share of as much as 50 percent may be required.
Colusa officials hope that implementation of the alternatives evaluated in the studies could prevent the river communities of Princeton, Colusa, and Grimes from being remapped by FEMA as special flood hazard areas, which would trigger high-cost flood insurance rates and strict building mandates.
The public is strongly encouraged to attend the meetings. ■