Stanislaus River flows could double in the coming days as the Bureau of Reclamation adjusts releases from New Melones Reservoir to handle what is expected to be a record snowmelt.
The Bureau has advised the offices of emergency services in both San Joaquin and Stanislaus counties of plans to change river flows. The impact on safety connected with activities in and along the river as well as the potential for flooding farmland on the riverside of levees is significant. It also will put further stress on the levees.
The river is currently flowing at 4,000 cubic feet per second or the equivalent volume of 4,000 basketballs passing a given point in one second.
The Bureau is mulling options that could increase the Stanislaus River flow to 8,000 cubic feet per second in the coming days. With the reservoir at just over 2 million acre feet — it has a 2.4 million acre foot capacity — the Bureau needs to make a determination of how they best can safely control inflow.
Driving the decision as well is the fact the peak snowmelt usually hits in late June or early July.
Two options being given serious consideration evolve around whether to try to cap the reservoir at 2.1 million acre feet or let it go to 2.3 million acre feet in the coming days. A lot of it has to do with how hot weather accelerates the snow melt. The snowpack on the Central Sierra watershed that includes the Stanislaus River watershed was at 196 percent of normal as of May 1.
If the Bureau goes with 2.1 million acre feet, the flows will nearly double and start fairly soon and continue for 60 days. Flows through the powerhouse at New Melones are restricted to a maximum of 8,000 cubic feet per second
The 2.3 million acre feet option would require kicking up flows to 6,000 cubic feet per second and continuing them for two months.
While either increased flow would put additional pressure on levees, releases of 8,000 cubic feet per second would flood the river farmland and possibly part of Ripon’s Jack Tone Golf Course. Sustained water could kill orchards along the river that are primarily planted in walnuts.
To contact Dennis Wyatt, email dwyatt@mantecabulletin,comn