Friday, March 25, 2016

California Still in Debilitating Drought

We are late in the California rainy season. In Northern and Central California rivers are filling to their banks, and reservoirs are swelling. The reason is rain, rain and more rain. 

Up the Sierra Nevada mountain range, the snowpack is near normal, which means rivers will continue to flow strong and refresh the reservoirs as snowmelt steps in to replace the lucre of falling precip. Nine months ago, after three years of significantly below normal precipitation, many reservoirs were at record or near-record lows; the U. S. Government said 99.9 percent of the Golden State was in drought. Now with many reservoirs filling up and spillways here and there opened to create capacity for snowmelt or future rains, Uncle Sam says 98.6 percent of the state is still in drought.

Look see at the Drought Monitor put out by USDA, NOAA and the Department of Commerce (if a rating system has three government agencies and all their Schedule C appointees, life-tenured bureaucrats and scientists behind it has gotta be really, really good).

The Los Angeles Times seems is a bit quicker on the uptake.

California's largest reservoir filling too fast thanks to El Nino, must release more water

The El NiƱo-fueled storms that have swept through Northern California in recent weeks have swelled some of the state’s largest reservoirs to encouraging levels even as the state's drought persists.
One of the biggest beneficiaries has been Lake Shasta, a keystone reservoir of the Central Valley project, which serves California growers.
To make room in Shasta for water from last weekend’s storms, the Federal Bureau of Reclamation ramped up releases from 5,000 cubic feet per second to 20,000 cubic feet per second on March 18. It was the first time since 2011 that the bureau released water into the upper Sacramento River at such a rapid rate, said spokesman Shane Hunt.
Officials began slowing the releases again on Wednesday, Hunt said. The rate is expected to return to around 5,000 cubic feet per second by Monday. 
“We never got to the point where the increased releases drew the lake down at all,” Hunt said. “We just slowed how fast we were gaining.”
Lake Shasta, he added, is “still gaining storage and will continue to do so.”
Lake Shasta is the most important water resource in the state.
Shasta Division consists of a pair of large dams on the Sacramento River north of the city of Redding.[4] The Shasta Dam is the primary water storage and power generating facility of the CVP. It impounds the Sacramento River to form Shasta Lake, which can store over 4,500,000 acre feet (5,600,000 dam3) of water, and can generate 680 MW of power.[5][6]Shasta Dam functions to regulate the flow of the Sacramento River so that downstream diversion dams and canals can capture the flow of the river more efficiently, and to prevent flooding in the Sacramento-San Joaquin Delta where many water pump facilities for San Joaquin Valley aqueducts are located.[4] The Keswick Dam functions as an afterbay (regulating reservoir) for the Shasta Dam, also generating power.[7][8] 
The Sacramento Canals Division of the CVP takes water from the Sacramento River much farther downstream of the Shasta and Keswick Dams. Diversion dams, pumping plants, and aqueducts provide municipal water supply as well as irrigation of about 98,000 acres (4,000,000 dam2).[9] The Red Bluff Diversion Dam diverts part of the Sacramento River[10]into the 110-mile (180 km) Tehama-Colusa Canal, the 21-mile (34 km) Corning Canal and a small reservoir formed by Funks Dam.[11] Five pump plants take water from the canal and feed it to the Colusa County water distribution grid.[9]

Here is the up-to-date water storage graph for Lake Shasta. Notice last week's kink caused by the Bureau of Reclamation spillway openings. 

Lake Shasta is filled to 87 percent of capacity, 109 percent of normal for this day of the year, and 100 percent of the average seasonal peak. Its 3,944,441 stored acre feet are about 50 percent more than the same day last year, more than double the storage during the debilitating 1976-1977 drought, and just a few ticks below the drought busting season of 1977-1978. Shasta would be more than 90 percent full if the spillways had not opened.

Following is the Lake Shasta picture for the last month in numbers. RES ELE is the reservoir elevation (water level), STORAGE is the water stored in acre feet, RES CHG, is the daily change in water stored, OUTFLOW is the water outflow, INFLOW is the water inflow, EVAP is water lost to evaporation, PPT INC is daily precipitation and RAIN is precipitation for the rain season to date. Accumulated rainfall for the season is 59.81 inches. That's five feet -- a lot of water.

SHASTA DAM (USBR) (SHA)Elevation: 1067' · SACRAMENTO R basin · Operator: US Bureau of ReclamationProvisional data, subject to change. Query executed Friday at 14:20:52   clock

Note: Reservoir Flows are daily averages.
Warning! This data is preliminary and subject to revision.

Precipitation at Mount Shasta since Christmas is well above average.

The period total of 27.6 inches is 44.4 percent above the normal.

Lake Oroville is the second largest reservoir in California. Its story and rapid recovery are similar to Lake Shasta's. Oroville is at 84 percent of total capacity, 113 percent of its daily average and 100 percent of its average yearly peak. 

Even smaller Sierra Nevada reservoirs like San Pedro (80 percent of normal, up from 70 percent on March 1, 59 percent on February 1, and 53 percent on January 1) that remain below normal, are sharply above last year's level and the historic 1976-77 lows, and are filling at a rates should bump up against -- and possibly exceed -- normal by the end of the wet season.

These reservoirs will continue to fill because they will be recharged by the melting of the ample snowpack.

Looking at smaller urban reservoirs in Northern California that supply city and suburban water systems, the news is excellent as well.

For example, in the Marin Municipal Water District, Marin County, north of San Francisco, the reservoirs are full.

Reservoir Storage (total capacity 79,566 acre-feet)
  Alpine, Bon Tempe, Kent, Lagunitas, Nicasio, Phoenix, & Soulajule ReservoirsAcre-
% of
Storage as of 3/24/201679,566100.00%
  Storage for this date last year76,02095.54%
  Average storage for this date72,82391.53%
Current storage (79,566 AF) is 109.25% of the average storage (72,823 AF) for this date.

The Sonoma County Water Agency reports neighboring Sonoma County's reservoir water levels are above water supply targets. As indicated by the downward kinks in the below graphs, Sonoma water is being released to reserve capacity for flood control.

Water Storage Graph

South of San Francisco, the data for the Santa Clara Water District are more difficult to interpret, but after digging around, we find the news is positive all around as well. Four out of the eleven reservoirs are full and a fifth, Coyote now 89.8 percent. The district's largest reservoir, Anderson, is reportedly only 57.3 percent full based on its 90,373 acre feet capacity, but that is not actually so.

Here is the scoop on Anderson Reservoir.
C1: Anderson Dam Seismic Retrofit
Anderson Reservoir is currently limited to 68 percent of its capacity due to seismic concerns, costing Santa Clara County valuable drinking water resources. This project covers earthquake retrofitting of Anderson Dam to improve reliability and safety, and returns the reservoir to its original storage capacity.

Anderson Dam creates the county’s largest surface water reservoir—Anderson Reservoir—which stores local rainfall runoff and imported water from the Central Valley Project. The reservoir is an important water source for treatment plants and the recharge of the groundwater basin. Besides restoring drinking water supplies, the upgrade also supports compliance with environmental regulations. The district’s regular reservoir releases ensure that downstream habitat has healthy flows and temperatures to sustain wildlife.

A breach of Anderson Dam at full capacity could have catastrophic consequences, including inundation of surrounding land more than 30 miles northwest to San Francisco Bay, and more than 40 miles southeast to Monterey Bay.

The current capacity is actually 61,810 acre feet, meaning Anderson Reservoir is 83.3 percent full and will likely fill up to its practical capacity in April. Total storage for all Santa Clara reservoirs is then about 80 percent of capacity (instead of 65.3 percent).

When reservoir storages get up to 200 percent we will check back to see if Club Fed has called off the Drought Monitor. Cheers.

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