When we overlay supply and demand, we get an idea where water availability is limited. These are the red areas in the map. The top shows surface water availability which is the ratio of consumptive water use and annual low season streamflow (red areas are where consumption is 70 or more of the flow). The bottom is for groundwater where we show the ratio between pumping and sustainable recharge. All these are at a HUC 8 watershed level (or 330 watersheds) across the conterminous U.S.
Just a map showing the footprint of WECC and ERCOT, the time frame is 20 years. Note that our focus has been on the US portion of WECC.
A unique aspect of this project is that it is the first time that energy planners and water managers have worked together toward integrated energy-water planning at this scale.
Note that this is a team effort, and the various partners.
In this sense water forms a constraint in terms of availability and cost on WECC/ERCOT’s planning process. Our task is to map water availability and cost throughout the west. Note that we consider 5 unique sources of water, 3 potable and 2 non-potable. Unappropriated water means there is unused water available in the stream or groundwater and can be obtained by simply requesting a permit/water right from the state water management agency. Appropriated water is that water that is likely to be available for transfer from another use, usually irrigated agriculture. Here the water right is purchased, the old use abandoned while the water use is transferred to a new use like thermoelectric generation. Non-potable sources are pretty self explanatory.
Worked directly with states to collect data, including various measures of water supply, water demand, and institutional controls on water use.
None of these measures alone tell us how much water is available for use. As such, the available data had to me combined into metrics that provide a comparable measure of water availability across the entire western U.S. To help us develop acceptable water metrics we convened a group of water managers to help us in developing the metrics.
Here we map water availability for the 5 sources of water along with the projected new demands for water in the non-thermoelectric sector (municipal, industrial, mining, agriculture), shown in the bottom right, for the next 20 years. Here availability is mapped at the HUC8 watershed level or about 1200 watersheds across the West. We use a non-linear scale where white indicates no available supply, hot colors indicate limited supply and cool colors indicate good supply. A supply of around 500 AF/yr. is generally required for a small gas plant (yellow/green color). Note big differences across the different supplies. Big areas of no availability of unappropriated surface and groundwater. Note that California shows no availability for any potable supply as they have regulations in place that prevent use of potable water for thermoelectric development.
Here we aggregated the availability across the different supplies of water and subtract the projected growth in demand from 2010-2030. Two maps are developed. The left map is where we only aggregate with unappropriated surface and groundwater as the aggregate supply (the least expensive water, and that which is traditionally considered for available supply). The map on the right aggregates all five water sources. Where the watershed is white that means there is insufficient supply to meet projected demand over the next 20 years. In terms of unappropirated water, large fractions of the west lack sufficient water to meet future demands. However, when all sources of water are considered much fewer basins lack the needed water to meet future demand (at least for the next 20 years).
However, the question is whether we can afford to develop these non-traditional sources of water. Here we map out a rough measure of water cost by HUC8 watershed. Hot colors represent high costs. White designates basin with no supply of that source. Costs include such factors as the cost to purchase or lease the water, cost to transport the water to the power plant, costs for treatment of the water and disposal of the resulting concentrates. Capital costs are amortized and combined with associated O&M costs (electricity, labor, expendables). There is roughly a 40 fold increase in costs between the appropriated water (what we are used to paying) and that for brackish water. Note that no cost is estimated for unappropirated surface water as the only real costs are for the permitting process which would be involved with each of the other 4 sources.
In a similar fashion to the water availability and cost metrics we are also developing an environmental risk metric to help identify regions were water development might be limited by sensitive environmental conditions. Developing maps for both surface and groundwater. Largely work by Argonne Nat Lab.
Here is a comparison of projected in thermoelectric water consumption across 6 of the scenarios. Here one can see the mix of basins vary, variation in watershed-to-watershed water use, and the overall intensity of water use. You can also see which basins thermoelectric development was limited by water availability (watersheds outlined in red).
Data will be made available through a decision support interface hosted by the Western States Water Council. The interface will allow visualization of the data, interaction, as well as the capacity to download.
Water in the West - Session 2 - Vince Tidwell
Photos placed in horizontal position
with even amount of white space
between photos and header
Where Will the Water Come From? Review of Water
Availability in the West
Vincent Tidwell, Barbara Moreland, Katie Zemlick, Barry Roberts and Howard Passell
Sandia National Laboratories
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed
Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
Water Limited Basins
WECC and ERCOT are
o Siting of new power
o New transmission
Technical Support Team
Sandia National Laboratories
Argonne National Laboratory
Pacific Northwest National Laboratory
Idaho National Laboratory
National Renewable Energy Laboratory
Electric Power Research Institute
University of Texas
Key Water Sources
Unappropriated surface water
Appropriated water (rights
Shallow brackish water
Utilized State Water Data
Mean Gauged Streamflow
Administrative Control Areas
• Data on “available water” are rare
• As such, metrics were estimated from available
• Assisted by volunteer team from WSWC
Bret Bruce (USGS)
Dan Hardin (TX)
Sara Larsen (WSWC)
Dave Mitamura (TX)
Andy Moore (CO)
Ken Stahr (OR)
Todd Stonely (UT)
Steve Wolff (WY)
Dwane Young (WSWC)
Unappropriated Surface Water
Consumptive Demand 2010-2030
Water for Development
Unappropriated Water Sources – Change in
All Water Sources – Change in Demand 2030
Relative Cost of Water
Cost to Retrofit
Technology Conversion Type
With wholesale cost of electricity about
$40/MWh*, many retrofits could be
accomplished at levels that would add less
than 10% to current power plant generation
Cumulative Frequency Plot of
Cost to Retrofit
• Many of the
• High growth
Cost to Retrofit Aggregated at 8-Digit Watershed Level
Water Use Data Exchange (WaDE)
• Use Web Services to
• Data Stay at the
Source (i.e. the
• Provide transparent
link between state
data and integrated
• Link to metadata
• Changes in state data
reflected in metrics