Clark Bypass cropped

The Sutter Bypass looking north; photo by Andrea Clark

It feels like Monday morning’s installment should start with a rousing round of “rain, rain, go away, come again another day, Californians want to play!”  With even more storms set to hit Northern and Southern California, the rain totals continue to rise and Mother Nature once again shows her awesome power.  Today’s installment is focused on short summaries of events from around the state.

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Here’s a recap of the last couple of days in the flood protection world:

1. DWR further reduced outflow from the primary spillway at Oroville Dam from 70,000 cfs to 60,000 cfs to 55,00 cfs, before announcing on Sunday at 2:00 that the outflows would be increased to 60,000 cfs again.  DWR reported that the initial reductions in flow had allowed assessment teams to view debris buildup and dredge debris piles below the flood control spillway.  DWR further shared that despite current inclement weather, work was continuing on the area below the spillway, the monoliths, access roads, and various eroded areas created by emergency spillway runoff.  Also, rock, aggregate, and cement slurry continued to be placed into areas affected by erosion with work continuing 24 hours a day.  On Sunday, DWR reported that the increases in releases (from 55,000 cfs to 60,000 cfs) were typical of normal flood control operations and were in anticipation of forecasted weather conditions to balance water flow in and out of the reservoir.  Once again we present a helpful graphic from public.tableau.com which shows releases and inflow on the top half of the page and water elevation on the bottom (note that as promised, DWR has created 50 feet of new flood storage in the reservoir).

Tableau Oroville

 

2. As reported by the local and national media, the town of Maxwell in Colusa county flooded, with approximately one foot of water affecting the small community.  According to the 2010 census, Maxwell had 1,103 residents living in 365 homes.  A largely agricultural community, it was affected by rivers, creeks, and canals rising, as no levees protect the community.  Maxwell was recently identified as part of the State’s Central Valley Flood Protection Plan as a small community in need of flood protection, and it is on the list for a possible grant from DWR to explore that possibility.  The picture distributed by the National Weather Service was certainly worth more than 1,000 words.

National Weather Service Aerial Photograph of Maxwell

National Weather Service Aerial Photograph of Maxwell

3.  Meanwhile, this impressive water year continues in other parts of the state. On Friday the Los Angeles area was hit with a powerful storm, bringing two to five inches of rain – along with high winds – throughout Southern California. Flooding shut down parts of Interstate 5, the threat of mudflows led to an evacuation order in the city of Duarte for about 180 homes, and more than 100,000 people across Southern California lost power. See here for a summary of the storm’s impacts and associated clean-up efforts.  While not as impressive as precipitation totals in Northern California, Southern California’s precipitation totals are well above average, with downtown Los Angeles currently at 200% of average rainfall to date, and at 96% of total annual rainfall with much of the water year remaining (see here for current water year totals throughout the state).

4.  For a preview of the storms about to hit California, we recommend Accuweather or the National Weather Service, both of which have some very useful graphics.

 

For more detailed information about current storage, inflow, and outflow from Oroville Dam, we still recommend the California Data Exchange Center. Additional sources of information on this incident can be found on the DWR website and DWR has shared this phone number for public updates: 530-872-5951.

That’s it for today. Please check back as we continue to update you on how the system is doing.  And stay dry!