WATER PLANNING
by Dr. Justin C. Thompson
HOW MUCH WATER WILL WE NEED ARE WATER SUPPLIES SUFFICIENT IN THE FUTURE? TO MEET THESE NEEDS?
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exas addresses these questions every five years through a regional water planning process. The key goal of this process is to ensure Texans have sufficient water to meet their needs during a repeat of the most severe drought on record. To accomplish this, 16 regional water planning areas—each composed
IF NOT, WHAT WILL THE IMPACT OF WATER SUPPLY DEFICITS BE AND HOW MIGHT WE AVOID THEM? of at least 12 statutorily required interest groups—evaluate population projections, water demand projections, and water supply estimates over a 50-year planning period. These identify potential water shortages and recommend water management strategies to resolve them. Regional water plans are then
What do these planning documents say about the future of water in the tri-county1 area? Water Demand: Population growth is a critical driver of increasing water needs. The population of the tri-county area is projected to increase by 130 percent or 1.3 million people over the 2020-2070 planning period. The majority of this growth is expected in Williamson County (+1.012M) and Bell County (+316,000) while Milam County population growth is minimal by comparison (+6,000). More people generally means more water is needed. Consequently, water demand in the tri-county area (Figure 1) is projected to increase by 92 percent, or nearly 220,000 acre-feet/year with 95 percent of that increased demand arising from municipal uses. Most of the increased water demand is expected in Williamson County (+167,000 acrefeet/year) and Bell County (+52,000 acre-feet /year) with only a modest increase in demand in Milam County (+832 acre-feet/year). Water Supply & Availability: To understand the future of water in the tri-county area it is important to first understand the distinction between water supply and availability as those terms are used in Texas water planning. Simply put, water supply is legally authorized for use, has existing infrastructure to connect it to water users, and can be relied upon during drought conditions. Available water considers only whether the resource could be relied upon during drought conditions. In this way, water supply is a subset of availability and may be increased by securing new water permits and/or building new infrastructure 1 Williamson, M ilam, and Bell Counties
20 WILCO BUSINESS REVIEW | 2022 • ISSUE 2
reviewed and approved by the Texas Water Development Board (“TWDB”) which uses the approved regional plans to prepare the state water plan. The 2021 Brazos G Regional Water Plan and the 2022 State Water Plan–Water for Texas are complete and available from the TWDB.
to connect reliable water to users. Water planners in Texas ultimately compare projected supply with projected demand to determine when and where Texans will have a surplus or deficit under drought-of-record conditions. Water Deficits – Water supply in the tri-county area is projected to increase by 14 percent or 30,000 acre-feet per year over the 2020-2070 planning period (Figure 2). However, this increase in supply is insufficient to satisfy increasing demand and, under drought-of-record conditions, water deficits are projected for the area throughout the planning period (Figure 3). For example, if the tri-county area were struck by drought-
