WATER SUPPLY PLANNING COMMITTEE
ITEM:		DISCUSSION ITEM
5.	DISCUSS STUDIES NECESSARY FOR WATER RIGHTS
Meeting Date:			September 11, 2012	Budgeted:	N/A
From:			David J. Stoldt,	Program/	N/A
			General Manager	Line Item No.:
Prepared By:			David J. Stoldt	Cost Estimate:	N/A
General Counsel Review: N/A
Committee Recommendation: N/A
CEQA Compliance: N/A

SUMMARY: Cal-Am and MWPMD have expressed a mutual interest in carrying out an Instream Flow Incremental Methodology (IFIM) study along the Carmel River in order to support applications for water rights permits from the State Water Resources Control Board. IFIM addresses the decision making environment as well as the techniques for quantifying incremental differences in habitat in a stream that result from alternative flow regimes. The IFIM procedure can determine the quality of spawning habitat (expressed in terms of weighted usable area) in relation to the streamflow.

An IFIM analysis is being sought by NOAA Fisheries for the Cal-Am Table 13 water rights application and may be required for future District applications for Permit 20808-B related to ASR. Cal-Am has indicated an interest in cost sharing if the District were to undertake the study.

RECOMMENDATION: The Committee should discuss and determine if it would like the District to move forward with an IFIM study.

DISCUSSION: Based on preliminary analysis, MPWMD staff believe that a rigorous IFIM study may indicate that current instream flow requirements set by SWRCB for diversions downstream of River Mile 15 (Rosie’s Bridge) may be higher that what is required to support spawning habitat. If an IFIM study showed that diversions could continue at lower flows, Cal-Am and MPWMD could both benefit from a lower and more consistent set of instream requirements for Phase 1 and 2 of Aquifer Storage and Recovery (ASR). This could result in a higher average yield for the projects.

MPWMD could also benefit in future water rights applications (the total amount of flow available for diversion could be higher) and Cal-Am could be able to divert additional water under a Table 13 right than their current estimate.

The underlying data for an IFIM study could also be used in other ongoing efforts, including monitoring of impacts from Cal-Am diversions to the vegetation in the streamside corridor.

Cal-Am believes an average of about 600 acre feet per year (AFY) could be available to Cal-Am from the Carmel River under a Table 13 water right (Cal-Am’s application to SWRCB is for 2,964 AFY). He said this diversion would occur during the same period as diversions for ASR. [ASR diversions can occur from December 1 through May 31 of the following year.] In previous discussions between the National Marine Fisheries Service (NMFS) Santa Rosa office and Cal-Am, Joyce Ambrosius, NMFS Fishery Biologist, has expressed an interest in carrying out an IFIM study in order to set instream flow requirements for Table 13 water rights. At the MPWMD-Cal-Am August 21 meeting, Cal-Am also expressed an interest in investigating whether the existing instream flow requirements set by SWRCB could be changed (i.e., lowered). Cal-Am has indicated that MPWMD should be the agency to carry out an IFIM study for the river.

MPWMD’s primary interest in an IFIM study is in updating the 2002 report “Instream Flow needs for Steelhead in the Carmel River” by the National Marine Fisheries Service. SWRCB has stated that unless better scientific information is presented, they are bound to use the recommendations from this study in water rights permits for the Carmel River. MPWMD would like a consistent set of standards to apply to Phase 1 and 2 water rights permits (20808A and 20808C) and any remainder permits issued under 20808B. An IFIM study could also remove some of the subjectivity that has crept into setting instream flow requirements for the river.

Kevan Urquhart indicated that inspections in the past few years at critical riffles during diversion season show that 70 cfs at Highway 1 may be sufficient for passage. If this can be confirmed, and an IFIM study can confirm that a change to a lower instream requirement would not result in an unacceptable loss of habitat (compared with 120 cfs), a scientific argument could be made that the existing instream flow requirement of 120 cfs could be lowered.

An IFIM study would likely compare usable habitat at a range of flows with current instream flow requirements as the baseline for comparison. A comparison would be made of usable habitat at both lower and higher flows than instream flow requirements. Up to a flow approaching winter peaks, it is likely – but not certain – that as instream flows increase, usable habitat increases. An IFIM study can be used to show incremental differences in usable habitat at various flows. Those decisions are made by balancing the need for water diversions with the need for providing habitat. IFIM can be used to show minimum and maximum amounts of usable habitat over a range of flows.

However, IFIM is not designed to produce a “best answer,” or to establish a minimum amount of habitat for a particular species, or to predict how many fish a particular set of instream flows would support.

Several different types of data can be used in an IFIM study, with flow and channel geometry being key components for studying effects of diversions on steelhead. MPWMD maintains comprehensive up-to-date time-series flow data and stream measurements that can be used for IFIM. High quality channel geometry data is also required for the study.

New advances in LiDAR (Light Detection and Ranging) sensors offer the possibility of mapping vegetation and creating a precise “bare-earth” model with one type of laser. In addition, a relatively new technology involving the use of a separate green laser has the ability to penetrate water and return bathymetric information to depths of up to 10 meters with the same aerial flight.

Larry Hampson suggested that Cal-Am and MPWMD could consider using such an alternative technology to monitor the streamside corridor in place of the annual aerial photographs required as a condition in the Four Well Agreement and to examine the usefulness for an IFIM study.

EXHIBIT

None

U:\staff\Board_Committees\WSP\2012\20120911\05\item5.docx