ADMINISTRATIVE COMMITTEE
4.	AUTHORIZE EXPENDITURE FOR ASSISTANCE WITH BUILDING A GSFLOW MODEL FOR WATER RESOURCE PLANNING
Meeting Date:		August 12, 2013	Budgeted:	Yes
From:		David J. Stoldt,	Program/	Augment Water Supply
		General Manager	Line Item No.:	1-8-1 / 5-7860.19
Prepared By:		Thomas Christensen/	Cost Estimate:	$127,908
		Jonathan Lear
General Counsel Review: N/A
Committee Recommendation: The Administrative Committee reviewed this item on August 12, 2013 and recommended __________________.
CEQA Compliance: N/A

SUMMARY: Staff proposes to retain Huntington Hydrologic and Right-on-Q Hydrogeology to assist the District in developing a GSFLOW (Groundwater and Surface FLOW) model to provide the District with the ability to conjunctively model surface water and groundwater in the Carmel River Watershed for water resource planning. GSFLOW is an integrated model that uses the Precipitation Runoff Modeling System (PRMS) for surface water and the Modular Groundwater Flow Model (MODFLOW) for groundwater modeling. The model will be constructed in two phases, the first is the PRMS component, and the second is the MODFLOW component. These two components are combined into GSFLOW. This model will replace the Carmel Valley Simulation Model (CVSIM) which is outdated and no longer operable. GSFLOW was selected because it is built on the United States Geological Survey (USGS) MODFLOW code which is recognized internationally in water resource planning and has a history of use as a scientific tool in legal proceedings. Any water supply solution for the Monterey Peninsula, required to offset the State Water Resources Control Board ordered reductions on the Carmel River, will be dynamic and require various operational strategies and scenarios. GSFLOW can be used as a planning tool to predict changes in river flow triggered by changes in surface water diversions and groundwater extractions. These predictions will allow District Staff to quantify the impacts of changes in diversions and extractions on steelhead and riparian habitat, flows available for aquifer storage and recovery, and the drought resistance of the Carmel Valley Alluvial Aquifer. In addition, GSFLOW can predict changes in aquifer storage and Carmel River flows due to climate change. A GSFLOW model of the Carmel River Resource System will provide District staff the most up-to-date tools and position the District as the foremost authority on questions associated with water supply planning.

Huntington Hydrologic and Right on Q will provide Phase 1 (PRMS) services as described in Exhibit 4-A ($46,320), and Phase 2 (MODFLOW) services in Exhibit 4-B, ($69,960) including several visits to the District to help calibrate the new model.

RECOMMENDATION: Staff recommends approval of the expenditures not to exceed $127,908 in budgeted funds for assistance with developing a GSFLOW model. This amount includes a 10% contingency ($11,628) in the event that actual costs differ from current estimates. If this item is adopted with the Consent Calendar, the General Manager would be authorized to enter into an agreement for services with Huntington Hydrologic and Right-on-Q for a not-to-exceed amount of $127,908.

IMPACTS TO STAFF/RESOURCES: Funds for this work are identified in the proposed FY 2013-14 Budget, Program Line Item 1-8-1, Water Supply Projects – Water Allocation/Water Rights. It should be noted that the hybrid approach of utilizing District staff in conjunction with consultants not only saves the District approximately $60,000 in consultant fees, it also provides District staff with technical knowledge of model development. The requested contract ($127,908) includes a 10% contingency.

BACKGROUND: Up to 2005, the District relied on CVSIM, which was an operational model developed in 1983 to run on the Naval Post Graduate School Main Frame Computer using the Fortran programming code. Due to a lack of access to the Naval Post Graduate School Campus, advancement in computer hardware and software, and retirement of outdated hardware, currently there is no operable version of CVSIM.

Project 8 of the Integrated Regional Water Management Plan Update performed an analysis of the modeling needs and contrasted those with the current abilities of the District. The project identified the need of District staff to develop a fully integrated surface water – groundwater model to better manage the water resources of the Monterey Peninsula. This work established that CVSIM only predicted flow in the Carmel River at 4 locations, and in order to better understand and manage the Carmel River and Alluvial Aquifer, a greater predictive ability was needed; especially when modeling the effects of changes in water resource strategies and operations on the resources. In addition, this work identified CVSIM as an operational model that did not physically represent the system as a whole, but rather simulated water demand and pumping without taking into account groundwater flow and its effects on surface water availability. The conclusion of the study is that the District should identify a path forward to replace CVSIM with a model that (1) can simulate the physical processes of the Carmel River Watershed, (2) is built on peer reviewed and industry accepted code, and (3) can be operated and maintained in house for the foreseeable future. Following the recommendations of this study, staff has identified GSFLOW as the model that best meets the outlined requirements and will give the District the ability to carry out water supply planning, secure future water rights from the Carmel River, and predict the effects of climate change on the resource.

EXHIBITS

4-A PRMS Detailed Budget

4-B MODFLOW Detailed Budget

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