Workers brach River’s mouth to avert Jenner flooding — After recent days of alternate openings and closings of the Russian River’s mouth caused by offshore winter storm action and seasonally high King tides, Sonoma Water crews finally gained
After recent weeks of high and dangerous surf that took four lives along the Sonoma and Mendocino ocean coast, accompanied by King Tides and offshore storms that kept closing the sandbar at the mouth of the Russian River, Sonoma Water work crews on Tuesday were finally able to breach the blockage and eliminate the threat of flooding to the town of Jenner.
The closed mouth allowed the river’s level to rise by almost six feet, closing the Sonoma Coast Visitor’s Center in Jenner and putting town residents on high water and flooding alerts. Sonoma Water workers gained access to the river’s sandbar at mid-day Tuesday when a large backhoe dug a trench to release river water into the ocean.
The same high-water scenario played out last week when storm waves were deemed too dangerous for work crews to attempt an artificial breach. But receding wave action on Thursday opened a small outlet without artificial help. But then the mouth closed again the very next day.
Two small children and their father drowned in the high surf on Jan. 3 at Blind Beach, just several hundred yards south of the river’s mouth at Goat Rock Beach. A Mendocino man drowned last weekend when he fell from a cliff into the ocean.
Heavy surf warnings remained in place this week as a series of high tides and continued storm action kept public access to Goat Rock and the river’s sandbar closed.
Closure of the river’s mouth is also aided by a lack of rain and upstream river flows. Without enough river current, the ocean’s wave action is allowed to build up the sandbar. On Tuesday, the river flow was 411 cubic feet per second as measured at Hacienda Bridge.
Sonoma Water, the county’s water and sewer agency, holds several permits to manage the Russian River estuary, including one from the U.S. Army Corps of Engineers that allows it to mechanically breach the sandbar to alleviate potential flooding and help manage the lower river’s fisheries and protections for pinnipeds (harbor seals and sea lions.)
Attempts to control the Russian River’s opening at the ocean has a long history. In the 1930s a long concrete jetty was constructed to keep the mouth open through the various seasons rain, summer droughts and violent winter storms. The jetty was never deemed much of a success and it was almost totally removed a few decades ago. Remnants of the concrete barrier can still be seen at the sandbar.
Prior to control by Sonoma Water beginning in 1994, private Jenner residents and others would artificially breach the sandbar when flooding was threatened. It is now illegal for such activities.
