In addition to creating new monitoring and reporting requirements, the 2009 Water Package also created a Delta Watermaster. Watermaster Craig Wilson will be presenting a report on “The Reasonable Use Doctrine and Agricultural Water Use Efficiency” to the Delta Stewardship Council next week.
The report’s premise is that inefficient use of water is unreasonable use under the Reasonable and Beneficial Use Doctrine. This report focuses on agriculture because “small changes in agricultural water use efficiency can produce significant amounts of ‘wet’ water and California’s agricultural sector, which has tested and proven many conservation practices, is in a position to identify economically justified and locally cost effective water management techniques that retain the value of return flows to both downstream users and other environmental beneficiaries.”
The report continues, “Maximizing the efficient use of water by projects that reduce consumptive water use is particularly important for the Sacramento/San Joaquin Delta. More efficient use of water upstream of the Delta can increase water flows into the Delta. More efficient water use within the Delta can increase Delta outflows. Reducing the amount of agricultural return Delta flow, both upstream of and in the Delta, has important water quality benefits.”
In terms of water use efficiency, it’s hard to beat the system already in place in the Delta. But Delta reclamation districts, already under the microscope, wonder whether this is another tool for scrutinizing diversions. The report notes that the reasonable use doctrine may be applied to an unreasonable method of diversion, even if the diverted water hasn’t been wasted or unreasonably used. Who gets to determine whether a method of diversion is unreasonable?
The intention seems to be to apply these principles to agricultural water use efficiency statewide. The report suggests further studies, including finding out how much water could be saved by switching to a different variety of a crop type that uses less water. We’d like to see the Watermaster go further and look at how efficient it is to commit to irrigating permanent crops in arid parts of the state.