The Water Board will be playing “Gotcha!”

The 2009 Comprehensive Water Package created new requirements for water users to monitor and report diversions.  Beginning in January 2012, users are supposed to keep monthly records of water diversions.  Delta water users are a prime target of this requirement, but it’s hard to see how the monitoring and reporting will yield useful information in the Delta.

That’s because in the Delta, much of the diverted water that is not consumed by crop growth returns to Delta channels as runoff or percolates into the ground and returns to channels as seepage.  In some cases, Delta reclamation districts pump irrigation water back into communal channels at their own expense, and it is available for additional use in the Delta.  The 2009 legislation doesn’t seem to provide any way to account for this kind of reuse.

Monitoring diversions emphasizes quantity of data over quality of data. It also allows for less attention to water quality.  In other areas of California, diverted water that doesn’t evaporate may end up in impaired groundwater basins, and runoff may be degraded by accreted salts.  Percolation and seepage in the Delta have the effect of filtering water and in many cases returning higher quality water to the system.

The danger with the new monitoring requirements is that the data requested may be of little or no value in solving State water issues on a broad scale.  The proposed monitoring systems would be an onerous expense to water users, and in fact, this directive could lead to overuse of water by surface diverters for fear that future diversions may be curtailed.

Delta water districts have discussed how to properly implement this legislative mandate in such a unique hydrological region.  In addition to questioning the value of the information the monitoring will yield, they wonder how to collect the data in a cost effective way.  (The legislation specifies – in § 5103 (e) – that  “Nothing in this paragraph shall be construed to require the implementation of technologies or practices by a person who provides to the board documentation demonstrating that the implementation of those practices is not locally cost effective.”)

As it stands, several working groups have been convened and a substantial amount of State Water Resources Control Board (SWRCB) staff time has been dedicated to framing a regulatory outline of how state water users may best comply with this legislative whim.

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