Increased Merced River flows to aid salmon migration can pose risk to people, officials say

The public is urged to exercise caution in and around the Merced River below the new Exchequer and McSwain dams, as increased water flows are scheduled to take place this week and into the next in an effort to aid salmon migration and spawning.

The increased flows are expected to begin Thursday, Oct. 16 and on Tuesday, Oct. 21, according to the Merced Irrigation District. The increased flows are to support the migration of the Chinook salmon, but could pose potential risks to recreational users of the river downstream from the New Exchequer and McSwain dams.

MID said pulse flows released from the dams can result in sudden fluctuations in water levels downstream. MID Government Relations Manager Mike Jensen, said the Merced River’s current flow as of Wednesday is roughly 525 cubic feet-per-second. With the increased pulse flows, the river’s flow is expected to nearly double to roughly 1,000 cubic feet-per-second over the weekend, before decreasing to roughly 180-200 cubic feet-per-second sometime next week.

“The idea with any pulse flow is generally to try and attract fish or salmon upstream,” said Jensen. Done in conjunction with the California Department of Fish and Wildlife, the intent is to aid the salmon in where they need to go while making the run this time of year.

MID said pulse flow releases help to ensure sustainability of the river’s fish population, specifically Chinook salmon which the district said are vital the region’s ecological health.

While the flows are helpful to attract salmon upstream for their runs from the Pacific Ocean, authorities say these conditions can prove dangerous for anyone in the river.

The MID advises people to avoid entering the river as swift moving currents and elevated water levels can pose a hazard. Swimming fishing and boating during the release period is strongly discouraged by the district.

Individuals should also exercise caution near riverbanks which can become unstable during periods of high flows.

Merced County Sheriff’s Office Captain Aaron Rosenberg who oversees the agency’s Dive Rescue and Recovery Team said anytime there are increased river flows there is chance for increased dangers in the water.

“A lot of times the water looks calm on top, but you really don’t know what’s going on underneath the surface,” said Rosenberg.

Increased flows can pose dangers beyond just cold fast moving water. Rosenberg said there is also a chance for more debris in the water which is one of the dive team’s biggest concerns every time they enter the water.

“Water carries a lot of weight behind it,” said Rosenberg. “If you have a tree, or a log, or something that you get wedged underneath or you get pressed against, sometimes it can be difficult to get off of there,” he said. “It definitely poses a significantly increased risk to rescue personnel as well as the public.”

While people who go into the water are advised wear a life jacket, Rosenberg said it is advised to have some type of flotation device, whether that be a life jacket or some other object even if they don’t plan on going in the water. The flotation device could help save a person should they accidentally fall into the water.

“If people aren’t prepared, then that’s when tragedy strikes,” he said.

While the sheriff’s office doesn’t plan on having an increased deputy presence near the river during this time of scheduled increased flows, recreation areas near the river throughout the county are routinely patrolled by deputies.