update2007_0725.html

July 25, 2007
Dear Stakeholders, Thanks for your interest in the LCRA-SAWS Water Project. This e-mail is another in our regular summaries of project developments that may be of interest to you.
MEETINGS
The next project update meeting will be held later this year. We will notify you when more details are available.

LCRA and SAWS recently widened the study phase to include two new topics that will be studied in 2008 to better understand uncertainties surrounding the proposed project. The new topics are climate change and risk analysis.

Climate change Study teams will evaluate how aspects of climate change such as temperature, evaporation and rainfall might affect the proposed project.

CH2M HILL recommended using a framework for assessing the impacts of climate change. The analysis is being done in response to comments from the science review panel.

Risk analysis LCRA and SAWS are standardizing risk analyses of the project by providing guidance to study teams on assessing the sensitivity of assumptions to results.

The proposed approach is laid out in a recent presentation. Individual studies already address the risks related to particular factors, however it is valuable to understand the interaction of these risks across the studies, according to the science review panel. Accepted methods of addressing risk are field-specific while the project requires a multidisciplinary approach.

The uncertainty of assumptions will be evaluated more methodically across the various studies.

INTERIM STUDY FINDINGS

Matagorda Bay health
Salinity in Matagorda Bay averaged between 16.4 parts per thousand and 26.4 parts per thousand of salts to water between 1970 and 2004, according to a report by Espey Consultants.

Bay and estuary salinity varies due to location, tidal fluctuations and freshwater inflow. By comparison, sea water salinity is approximately constant at 35 parts per thousand.

The report, Matagorda Bay Existing Conditions, describes current resources in the bay system so that possible effects from the proposed project can be understood.

The following resources are described:

Land use
Aquatic and terrestrial habitats
Wildlife and fisheries
Threatened and endangered species
County, state and federal conservation areas
Inflow and hydrology
Earth resources (geology, topography)

View the report.

Surface water availabilityThe water yield of the LCRA-SAWS Water Project could vary significantly, depending on groundwater availability, the size of the off-channel storage facility, evaporation rates, irrigation demands and environmental flow restrictions, according to an analysis by TRC.

The study, "Sensitivity Analysis of Modeling Refinements," is preliminary and only the initial phase of more comprehensive investigations being undertaken this year to better understand the LCRA water supply and delivery system.

The study is using an enhanced version of the water availability model for the lower Colorado River basin used by the Texas Commission on Environmental Quality.

View the report.

We hope you find these project updates useful and welcome your comments on the content and format.

For more information, please contact us at 1-800-776-5272, Ext. 7208 or lcrasawswaterproject@lcra.org.

Thank you,

Leah Manning
Program Manager
LCRA-SAWS Water Project

Gary Guy
Manager-Water Resources
San Antonio Water System