Report assesses impacts of Russian River lagoon at Jenner

<p>Allowing the sand bar at the mouth of the Russian River at Jenner to remain closed longer than usual creates a fresh-water lagoon that benefits young steelhead, according to biologists.</p><p>But it may also effect low-lying properties, water quality and the marine mammals that use the sand bar, according to a final impact report released Thursday.</p><p>The report was prepared by the Sonoma County Water Agency for its project at Jenner, which is being mandated by the National Marine Fisheries Service to improve the survival chances of steelhead.</p><p>“We are complying with the Russian River biological opinion that requires us once the estuary is closed to keep it closed during the summer to provide a nursery for steelhead,” said water agency spokeswoman Ann DuBay.</p><p>Young steelhead, which are listed as a threatened species, spend the summer at the estuary that forms at Jenner before they head out to sea. The intention is to create a fresh-water lagoon that lets the fish adapt better to ocean conditions.</p><p>The sand bar opens naturally during strong flows of the Russian River, but at other times when the water backs up, the agency will prevent nearby flooding by digging a shallow opening that is intended to let the fresh water out and minimize the salt water coming in.</p><p>According to the report, keeping the sand bar closed could lengthen the time that water is degraded in the lagoon.</p><p>Such mammals as seals and sea lions are also less likely to haul out on the sand bar when the mouth is closed, according to the impact report.</p><p>The agency received 203 comments on its draft report issued in December, the majority contending the report should also include the impact on water quality of lowering summertime flows in the Russian River that is also required by federal regulators.</p><p>A public hearing will be held Aug. 16 at the Board of Supervisors chambers in Santa Rosa.</p>