Posted on August 31, 2017
By Howard Yune, Napa Valley Register
Last winter’s fierce rainstorms have undone much of the recent work to clean up the Napa River’s shipping channel, and the city is taking a first step toward re-dredging the waterway – while awaiting a hand from federal disaster relief.
A project to remove storm-driven sediment from the River Park Marina gained City Council on Aug. 15, as part of a package that also may include new dredging efforts on the main river and at the Kennedy Park boat ramp south of downtown.
The Dutra Group of San Rafael will receive $538,000 to remove silt from the mouth of the marina entrance near south Napa’s Newport North condominiums.
Napa also may call on the company to dredge the Napa River for $1.21 million and clear the Kennedy Park launch for $318,900, for a total cost of $2.07 million, if it wins reimbursement from the Federal Emergency Management Agency for damage caused by the January and February storms.
The dredging campaigns would cover the same ground as the waterway maintenance performed in and near Napa over the past two years, including a late-2016 effort to remove shoals from 17 miles of the Napa River as far south as Vallejo – the first federally funded river maintenance since 1998.
Outside the Napa River’s navigation channel, city-led projects cleared the silt-choked Kennedy Park ramp last year and the River Park entrance in 2015.
What work crews had accomplished over more than a year, however, was largely reversed by two storm patterns bearing near-record rainfall.
Bay Area storms in the first weekend of January brought the Napa River to flood stage and led the city to open the gates of its downtown bypass channel for the first time. At its height, the city was receiving more than 2 ½ inches of rain every 24 hours with even heavier precipitation upstream of Napa. More storms struck at the Napa Valley a month later, triggering a flood watch in the city and flood warnings Upvalley.
The by-product of such violent weather was a surge of 23,000 cubic yards of sediment in the Napa River, according to city Public Works Director Jacques LaRochelle. At Kennedy Park, the boat ramp was fouled by the same 8,000 cubic yards of silt the city had removed the year before.
Permits FEMA issued river maintenance in 2016 remain valid for work this year, LaRochelle told the council, but environmental regulations leave little time to resume dredging before wintertime restrictions to protect plant and animal life take effect.
Source: Napa Valley Register
