BOARD02325

• Board Meeting Date: 3/22/2005
• Description: CF Section - Severance Tax Trust Fund Operational Account Recommendations
• Board Meetings - Doc Type: Memo

.

Water Planning Relationship: Colorado's Interstate compact obligations require that we deliver
water to New Mexico and Texas annually. A better understanding of the system wilI allow us to make
better planning and management decisions for Colorado's water users, avoid costly lawsuits, and
conserve more effectively, while maximizing our alIocations to ensure the economic viability of the
valley.

Recommendation: Staff gives a medium recommendation to this project because of the limited
funding available. This project should seek other funding sources such as the Non-Reimbursable
Investments from the Construction Fund.

11. SPDSS Groundwater Modeling Coordination

Beneficiary/Grantee/Contractor: CWCB, USGS, South Platte River Basin Water Users
Amount of Request: $50,000 Ranking: High

Product Produced: As part of the South Platte Decision Support System (SPDSS), the CWCB is
developing a groundwater flow model of the alIuvial aquifer system overlying the Denver Basin Region
and along the lower South Platte River downstream of the Denver Basin. The U.S. Geological Survey
(USGS) is developing a groundwater flow model of the bedrock and alIuvial aquifers in the Denver
Basin Region, scheduled for completion in late 2006, with funding from the USGS Office of Ground
Water. Both models will use the USGS ground-water modeling program MODFLOW. The USGS is
working in cooperation with the CWCB as SPDSS data colIection efforts progress.

.

There is a need for additional coordination between the modeling efforts of the State and the USGS so
that once their respective models are complete there is, in effect, one groundwater flow model for the
region (i,e., parameters, boundaries, and levels of complexity of the two models are essentially the
same), This study proposes to further coordination of the groundwater modeling efforts between the
State and the USGS in several ways including: ensuring various model parameters and boundary
conditions from the USGS model are reflected in the State's model; providing bedrock aquifer flows
from the USGS model to the State's alluvial ground-water model; enhancing the USGS model to a
similar level of detail as the State's model; incorporating the USGS Denver Basin model into the
SPDSS; and providing model results with which to update SPDSS databases upon completion of the
USGS efforts in 2007. Results of this study will include quality-assured databases, MODFLOW input
and output files, and GIS data sets for use by the SPDSS,

Water Planning Relationship: Results of proposed study will be incorporated in the South Platte
Decision Support System (SPDSS) meeting a regional data need and assisting the CWCB plan for future
water resource management in the South Platte River Basin.

Recommendation: Staff gives a high recommendation to this project because the benefits of this
project will enhance the data available for SPDSS.

Water Supply Planning and Finance Program

1. Diversion Structure Inventory

Beneficiary/Gran tee/Contractors:
Amount of Request:

CWCB, Agricultural Ditch & Reservoir Companies
$85,000 Ranking: High

9