|Table of Contents||Section 6 - Additional Supply from Water Conservation|
Water conservation is a potential means of reducing the projected water demand in the Sabine Basin, which effectively reduces the projected need. The TWDB has developed different conservation scenarios in their water use projections for municipal, manufacturing, irrigation and power uses. The base projections presented in Section 2 of this report incorporate an expected level of conservation.
In this section of the report, the municipal, manufacturing and power use projections were examined to determine how much water could be saved through advanced conservation Mining, livestock, and irrigation uses were not examined to determine additional savings through conservation because they represent only a very small portion of the overall water use in the Basin.
Municipal Water Use
Municipal water use calculations incorporate population projections, weather conditions and conservation assumptions. The unique combination of these considerations result in different municipal use projections. As discussed above, the projections used for this report include the "most likely" population, below normal rainfall and expected conservation. Additional conservation savings are projected under two other demand scenarios: the advanced conservation scenario and the low demand scenario.
The advanced conservation scenario reflects the demand reductions resulting from expediting the timing of regulatory requirements and adopting more aggressive conservation programs at the local level. The low demand scenario compares projected demands for average weather conditions with no conservation to average weather conditions with advanced conservation. This evaluates the impact of conservation efforts on municipal use during normal rainfall conditions. A summary of the projected municipal water use conservation savings is presented in Table 6.1.
Ten counties in the state account for approximately 77 percent of Texas’ total manufacturing water use. Two of these counties, Harrison and Orange, are located in the Sabine Basin. In addition, the industries that demand the largest portion of industrial water in the state (chemical products, petroleum refining, and pulp and paper) are all primary industries in the Sabine Basin. Manufacturing water use in the Sabine Basin is the largest projected use type, accounting for 61 percent of the total demand in 2050.
The manufacturing water use projections used for this report assumed low oil prices with no conservation. Other scenarios developed by TWDB address industrial growth based on oil prices and conservation measures indicated by the implementation of water efficient technologies in existing and new plants.
TWDB projections assume conservation savings accrue from the implementation of water efficient practices in manufacturing processes specific to each industry. Projections assume these practices occur as a result of market forces and the availability of improved technology. Table 6.2 includes data on manufacturing demands for both the "most likely" and low oil price scenarios, with and without conservation.
Power demand was projected using two different series: a High series that assumes current technology will continue unchanged, and a Low series that assumes new technology and conservation will result in net water savings. Steam electric power projections for this plan assumed the High water use scenario (with no conservation).
There are six counties in the Sabine Basin with either existing or planned power facilities: Gregg, Harrison, Hunt, Orange, Rusk and Wood. In 2050, the power demand is projected to account for 18 percent of the total water demand in the Basin. The potential exists to conserve up to 15,000 acre-feet per year by 2050 with aggressive conservation measures. Table 6.3 illustrates the projected conservation savings that could be realized if power facilities in the Basin adopt advanced technologies that Lower the gallon per kilowatt-hour water use.
Advanced water conservation savings contained in the TWDB water demand projections would suggest that adoption of aggressive conservation practices could significantly assist in meeting projected future water supply shortfalls. Combining projected savings for municipal, manufacturing and power categories could reduce the Basin’s total projected demand in 2050 by 73,300 acre-feet per year. The combined conservation savings by decade are shown in Table 6.4.
These projected amounts of water demand reductions, if realized, could address a significant portion of the Sabine Basin’s projected needs. However, a number of factors suggest that this level of aggressive conservation will be difficult, if not impossible, to achieve. These factors include:
The water use projections generated for this Plan account for conservation savings for municipal and irrigation use. The expected savings already incorporated in these projections (compared to no conservation) exceed 20,000 acre-feet per year. It is highly unlikely that additional conservation savings will be realized for municipal use without local commitment for aggressive conservation. There may be water conservation savings associated with manufacturing and power uses, but these savings are industry and market driven. They cannot be relied on by SRA as firm supply. In severely water supply limited locations within the Basin substantial reductions in water demands may be possible, and SRA should investigate targeting implementation of conservation measures for users in these areas. The local communities or industries can initiate aggressive conservation measures that would reduce water demands, but SRA’s role in requiring such measures is limited. Therefore, for planning purposes, it is assumed that there is no additional supply from conservation measures beyond those assumed in the water demand projections.