Flow Facts for Estuary Community Meeting

Monte Rio Community Center  

May 16, 2013


  • Lake Mendocino has a total capacity of 116,500 Acre Feet (AF).
  • Army Corps of Engineers (ACOE) controls releases from Lake Mendocino and Lake Sonoma dams from Nov. 1st  to March 1st  (unless threat of floods in March and/or April cause ACOE to take back control).  Their primary obligation is to manage Coyote Dam and Warm Springs Dam for flood control.
  • On Dec. 26, 2012, the Lake Mendocino contained 94,298 AF of water.(Note:  Our previous flow fact sheet circulated by email was based on some inaccurate data.  The following information has been revised based on correct data.)
  • One week later, on Jan. 3, 2013, the reservoir contained 68,874 AF of waterThe Army Corps of Engineers (ACOE) had released over 25,000 AF of water IN ONE WEEK!  (27%) The highest level achieved in Lake Mendocino since that time has been 72,537 AF of water.
  • On May 15, 2013, Lake Mendocino was at 59,300 AF, after three years of normal flows in the lower river. On May 15, 2009, the third year of draught conditions, Lake Mendocino was about 55,300 AF. If we have a hot summer, with this kind of ‘planning’, we may have a very difficult season.  SCWA should establish a local citizens group including various interested parties, to help develop plans to manage lower river issues.
  • Summer flows in lower river are determined by a complicated formula based on Lake Pillsbury water levels on May 31st of each year.  There is an excellent chance that flows in lower river will go down as low as 35 cubic feet per second (cfs), although probably not until later this summer. Flows at Hacienda are currently running around 300 cfs.  Recreational difficulties and water quality concerns become prevalent below 100 cfs.
  • In 2009, during a significant drought and critical dry conditions, August flows got down as low as 45 cfs, but most of that month, they averaged around 65 cfs, mostly because mandatory conservation was in effect.  Under normal circumstances, according to State law, flows must be maintained at a minimum of 125 cfs.  The rate of draw down is faster than in 2009, generating concern that there won’t be enough water for threatened Chinook migration in the fall.
  • If we have a hot summer, high water use by contractors will occur unless mandatory conservation is implemented.  Only this will convince water users that there is a serious problem.
  • If we also have high water use by agricultural operations, reservoir levels will go down very quickly.  Currently SCWA may have permission from the State Water Board to go as low as 35 cubic feet per second (cfs) at Hacienda this summer. If we had not lost that 25,000 AF in December and January, we would have no problems now.
  • Contractor water use went down considerably under 2009’s mandatory conservation requirements.  They have been creeping back ever since.  What is particularly revealing is that SCWA expressed deep gratitude for the increase on numerous occasions, since their budget had been severely constrained by the diminished water sales.  At contractor meetings, the relief at being able to sell more water was palpable. One never hears concern expressed at these meetings about losses experienced by the lower river community.  In addition, because of all around budgetary constraints suffered by all contractors, SCWA went to great lengths to keep water prices down so their customers would not complain.
  • Along with recreation, we are very concerned about water quality issues.  In 2009, Russian River Watershed Protection Committee (www.rrwpc.org) composed a 2009 Photo Project showing many examples of algae blooms in lower river, including one sample of toxic blue green algae.  The Russian River is impaired for temperature, excessive sediments, and bacteria (in certain locations).  All of these problems become greatly exacerbated during low flow.  In their application for the Temporary Urgency Change for 2012 (i.e., low flow request to State Water Board), SCWA included test results of several conventional pollutants.  The worst was phosphorus, followed by bacteria. Excessive phosphorus during low flows will cause proliferation of algae, invasive plants, and other biological nuisances.  Furthermore, these circumstances are all harmful to the fish, the main consideration in these flow changes.


  • Biological Opinion demands low minimum flows in lower river in spite of water quality impairments so the Jenner Visitor’s Center won’t flood.  Supposedly low flow will allow implementation of project to maintain closed mouth conditions at the Estuary so a fresh water lagoon will provide beneficial habitat for steelhead fish.
  • NOAA official, Patrick Rutten required Pescadero Creek to be breached at the Estuary last December because 200 to 400 steelhead die each year as a result of a CLOSED MOUTH.  The article stated (The Daily Journal, Dec. 29th & 30th, 2012, San Mateo), “During yearly months of disconnect, the temperature of the lagoon rises and decreases oxygen levels in the water, affecting the procreation and resiliency of the native fish.” (We suggest the nutrients don’t help either.)
  • Large amounts of algae were seen at Visitor’s Center recently even though it’s early in the season.  This is occurring even with river mouth open and is a sign of impaired water quality condition.

(Facts written and compiled by Brenda Adelman for RRWPC:  rrwpc@comcast.net)