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TUOLUMNE RIVER WATERSHED ANALYSIS

July 2014 Update

For updated information, please refer to the Sacramento-San Joaquin Basin Analysis Webpage. No further updates will be made to this page at this time.

The following information on projected water supply, demand and availability, prepared by the Division of Water Rights for the Tuolumne River Watershed, is being provided to assist water right holders in planning for water availability in the coming months. This information is the Division's best projection, based on current hydrologic data. These are estimates only and subject to revision and update.

Charts and Forecasts

The projected water supply for the Tuolumne River Watershed was developed using historical water supply data at both a 90% exceedance level and 50% exceedance level. The exceedance level is the likelihood, based on historical data, that the actual flow will exceed the projected amount. To determine which exceedance level best fits actual flow conditions, the Division is tracking the flows daily in acre-feet per day and comparing that to the monthly total amount projected by the Division divided by the number of days in the month to show acre-feet per day. The attached graph Adobe PDF logo shows this daily tracking.

  • Current Watershed Conditions
  • Curtailment Notices Issued
    • None, due to continuing, intermittent storm events.

  • Curtailment Projections
    • Pending
      • All post-1914 water rights.
    • Projected
      • Between May 20th and June 15th, junior pre-1914 water rights.
      • Between June 16th and July 15th, curtailment of remaining pre-1914 and riparian water rights, based on available water supply and priority. Any remaining supply must be shared on a correlative basis among riparian users.

Notes

  1. Curtailments can be lifted temporarily or permanently if water supply conditions improve.
  2. The State Water Resources Control Board may consider needs for limited diversions for public health and safety needs where there is no other water supply available for emergency human health, sanitation and safety needs.
  3. Diversions for hydropower generation, where all water is returned to the stream, may continue during curtailment.
  4. The curtailment notice does not affect water delivered by contract from state, federal or local agencies, unless the curtailment prevents an agency's ability to divert water under its water right. Contracts using water withdrawn from reservoir storage that had been collected prior to the curtailment are not affected.

Tuolumne River Watershed Boundary

Click Map to Enlarge