Napa County’s agricultural water users rely on both groundwater and surface water flow to provide frost protection and irrigation. Similar to other areas of the state, it is anticipated that Napa vineyard owners will rely on groundwater resources to make up any shortfalls in surface water availability.
Many vintners rely on the surface flows from the Napa River for frost protection, which is a court-adjudicated river. Each party holding water diversion rights under the 1976 court decree is allotted a certain amount of water from the river during a court-defined “frost season” (March 15-May 15). According to the decree, water right holders must cease all diversions from the river when flow levels drop to 10 cubic feet per second (cfs) or less. Napa has a watermaster, appointed by the State Water Resources Control Board, who oversees all diversion activity from the Napa River.
DP&F has collected data from the California Dept of Water Resources (CDWR) and discovered that the Napa River has never dropped below 10 cfs since CDWR began to collect the data in 1993; however it was very close in 1994, 2004, and, most notably, in 2013. (To review the Napa River’s cfs history since 1993, click here.) Due to the low precipitation we have experienced to date and a forecast calling for more sunny days, it is possible that river flows will not meet the 10 cfs level after March 15, requiring the Napa River Watermaster to stop all diversions. Consequently, property owners may have to rely more heavily on groundwater for frost protection and other water needs, to the extent it is a viable option.
Aggressive State Stream Diversion Enforcement Comes to Napa River Watershed
A number of property owners in Napa County, including wineries, recently have received a form letter from the State Water Resources Control Board entitled, “NOTICE OF POTENTIAL UNAUTHORIZED DIVERSION AND USE OF WATER, AND FAILURE TO FILE A STATEMENT OF WATER DIVERSION AND USE FOR DIVERSION OF WATER IN NAPA COUNTY.”
The letter states that the Board has identified a reservoir on the subject property that appears to be on a “class I, class II, or class III stream,” but has determined that there is no record of a permit authorizing diversions from the stream into the reservoir. (A class I stream is a stream where fish are always or seasonally present, a class II stream is a stream where fish are not present but certain aquatic species exist (frogs, salamanders, benthic insects), a class III stream does not support aquatic life.) The notice spells out the various civil fines for unauthorized stream diversions ($1,000 for failure to file a statement of diversion, plus $500 per day the violation continues if a statement is not filed within 30 days of Board notice), and gives the property owner three options:
1. Prove that you no longer own the property, or that there is in fact no reservoir on the property;
2. Prove that you indeed do have the appropriate permit or water right authorizing the diversion, or that you have been filling the reservoir with purchased water, groundwater, or other water not subject to the Board’s jurisdiction; or
3. Take corrective action within 60 days.
What is “corrective action?” The Board states that, “[n]ormally, an unauthorized diversion can be stopped, removed, rendered incapable of storing water, or legalized through the appropriative water right permit process.” Unfortunately, if a property owner wishes to apply for a permit to legalize an existing unauthorized diversion, the Board’s “Policy for Maintaining Instream Flows” (see here: www.waterboards.ca.gov/plans_policies/) states that after May 5, 2011, it will no longer approve water rights applications for reservoirs built with an onstream dam on streams designated as a class I or class II stream (see definitions above).
There is also the question of whether the Board is even correct in assuming that the subject reservoirs are the result of stream diversion.