Beginning today, people who plan to fish, boat and hike along the Stanislaus River below New Melones Reservoir need to watch out for rapidly rising and falling river levels over the next week and a half.

Government employees who run the dam at New Melones are planning a series of pulse-flow releases from the Golden State’s fourth-largest capacity reservoir.

About six miles downstream from Knights Ferry, river depths are expected to double from 3.2 feet to 6.4 feet at times at Orange Blossom, data and graphics from the California Nevada River Forecast Center show.

The federal Bureau of Reclamation runs the dam and controls water levels at New Melones. Reclamation staff say the planned 11-day series of controlled pulse-flow releases from New Melones are for flood-control purposes and are part of efforts to manage Chinook salmon in the river. New Melones was more than 80 percent full Thursday.

Bureau of Reclamation staff issued a statement saying, “Last year’s record-setting precipitation filled the reservoir, and increased flows are necessary to meet flood storage capacity requirements. The flows will be released in a pulsed sequence to minimize the likelihood of Chinook salmon spawning in areas that will be dewatered after the flood-control release is completed.”

Flows are expected to increase from 600 cubic feet per second early today, to peak at 2,500 cfs by 2 p.m., with three more peak flows around 2,500 cfs through Dec. 11, when flows will return to 600 cfs. Public information staff with South San Joaquin and Oakdale irrigation districts and Tri-Dam Project, holders of senior water rights on the Stanislaus River, are advising people, “If you're going to be on or near the river during that time, please be careful.”

Bureau of Reclamation dam controllers at New Melones did the same thing in early November and said it was for flood control purposes. Back on Nov. 3, they started an 11-day schedule of controlled pulse flow releases ranging from 700 cubic feet per second up to 2,600 cfs, with peak flows on Wednesday and Dec. 8 and 9.

As of Thursday afternoon, the man-made storage facility at New Melones was holding 148 percent of average for the date Nov. 30.

Contact Guy McCarthy at gmccarthy@uniondemocrat.com or (209) 588-4585. Follow him on Twitter @GuyMcCarthy.

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