Balancing Act: Weather, Irrigation, and Meeting the State’s Agriculture Needs

Water has always been essential to Texas agriculture, and irrigation remains its single largest use. Despite growing demands from cities and industry, agriculture—especially irrigation—continues to account for the majority of Texas water consumption. The state’s varied climate influences the demand from irrigation uses.

Rainfall Availability and Variations (2010-24)

Texas’s vast geography spans a wide range of rainfall conditions, from the lush coastal plains to the arid western reaches. This climatic diversity deeply influences water use in agriculture, particularly irrigation. There are 10 climate regions (see map) divided by the National Climatic Data Center. Those regions are grouped by similarities like temperature, rainfall, vegetation, humidity, and seasonal weather patterns. These regions help group areas with similar climate conditions, making it easier to track and understand long-term weather trends. Climate data from different locations within each region are averaged together to give a clearer picture of how conditions vary across the state.

Source: ETE Climate Regions

According to the precipitation data, average annual rainfall varies widely by regions—from just over 12.5 inches in the Trans Pecos to over 54 inches along the Upper Coast and in East Texas. Central and western regions, like the Edwards Plateau, Southern, and High Plains, receive less—typically between 19 and 25 inches—highlighting their heavier reliance on irrigation to support agricultural production.

In addition to average, the coefficient of variation (CV) is used to measure how much rainfall varies across different regions. It shows how unpredictable rainfall is—the higher the number, the more it swings year to year.

Unsurprisingly, the Trans Pecos again emerges as the most water-stressed region, with the lowest rainfall and the highest CV (0.34). High Plains also shows relatively high variability, making these two regions most dependent on supplemental water. Even the Lower Valley, with moderate rainfall around 28 inches, has a relatively high CV (0.28).

In contrast, North Central, East Texas, and the Upper Coast not only receive more rainfall—ranging from about 38 to 54 inches—but also experience more stable patterns, with CVs around 0.24. This relative consistency reduces pressure on irrigation in typical years, though these regions are still vulnerable to droughts.

Rainfall patterns closely align with how agriculture is distributed across Texas. In West and South Texas, where rainfall is low and highly variable—especially the High Plains, Trans-Pecos, and Edwards Plateau agriculture is heavily dependent on irrigation and tends to focus on drought-tolerant crops like cotton and livestock grazing, which is more adaptable to dry conditions. In contrast, East Texas and the Upper Coast, with their higher and more stable rainfall, support more rain-fed crop production, including hay, timber, and forage, and can sustain more intensive livestock operations due to more reliable pasture growth. This east-west divide underscores the link between climate and agricultural strategy.

Drought Severity and Irrigation Source Trends (2010-22)

The years between 2010 and 2022 featured two severe droughts, with 2011 standing out as one of the most extreme (see figure). During this year, over 96 percent of Texas experienced abnormally dry or drought conditions, with nearly 45 percent of the state facing “exceptional drought” (D4). Groundwater accounted for 73 percent of irrigation water that year. However, the most interesting trend appears between 2012 and 2014, when drought persisted at various levels. Groundwater use increased sharply, peaking at 83 percent in 2013, and surface water availability was likely limited due to low reservoir levels and streamflow, making groundwater the fallback.

Source: Texas Real Estate Research Center analysis of Texas Water Development Board data

In contrast, 2016 marked one of the least drought-impacted years of the decade— less than 4 percent of the state experienced any drought at all. As a result, the share of irrigation water drawn from groundwater dropped to 76 percent, while surface water use rose to 23 percent. This shift highlights a clear pattern: In wetter years, surface water becomes more available, helping reduce reliance on stressed groundwater aquifers.

By 2022, drought conditions had returned and 77 percent of the state was experiencing at least moderate drought (D1). That year, groundwater accounted for 78 percent of irrigation supply. While slightly below the 2012-14 peak, this still reflects a consistent trend: In dry years, farmers increasingly fall back on groundwater to meet irrigation needs.

Water Use Efficiency Over Time

To address long-term water constraints, Texas has moved toward more efficient irrigation systems. Efficiency refers to how much economic value—such as agriculture output—is generated per unit of water used. Analysis from selected years shows overall improvement in agriculture water use (irrigation and livestock use) efficiency.

Taking irrigation as an example, in 2010, the state generated about $1,180 per acre-foot of irrigation water (calculated by nominal values). By 2022, that figure had climbed to $1,713, reflecting gains in both irrigation practices and agriculture productivity.

The most notable jump occurred between 2020 and 2022, where irrigation efficiency rose from $879 to $1,713 per acre-foot, likely driven by a combination of water-saving technologies, and drought-induced pressure to maximize water use. Livestock efficiency also climbed steadily, from $29,275 to over $60,029 per acre-foot.

While year-to-year fluctuations still exist, often tied to weather and commodity prices, the overall trend shows that Texas agriculture is becoming more economically efficient with its water resources, especially in dry years when maximizing every drop becomes critical.

Disaggregating agricultural production data into crop and livestock sectors using USDA Census data allows for a more effective evaluation of improvements in water use efficiency. Notably, livestock production has demonstrated a faster rate of efficiency gains compared to improvements in irrigation use.

TWDB Projections and Irrigation Outlook

Looking ahead, the Texas Water Development Board (TWDB) 2022 State Water Plan projects that irrigation water demand will decline gradually over the coming decades. This is partly due to improved irrigation efficiency, reduced groundwater availability, and economic challenges tied to deeper pumping costs. In some counties, projected groundwater supplies fall below baseline irrigation demand, leading to adjusted demand forecasts that decline over time.

On the supply side, surface water availability is expected to decline slightly (about 2 percent) due to sedimentation in reservoirs. Annual existing groundwater supplies face a steeper 32 percent drop between 2020 and 2070, driven by managed depletion of the Ogallala Aquifer in the High Plains region and regulatory pumping limits on the Gulf Coast Aquifer in the Upper Coast region.

Despite projected demand declines, irrigation is still expected to have the largest unmet water needs of any sector. Many irrigation users will likely face ongoing water shortages in the decades to come.

The state’s diverse climate and geography create sharp differences in water availability and demand across regions. Even though improvements in irrigation efficiency offer some relief, the persistent unmet needs highlight the urgency for stronger action. There is still room to improve water supply, especially in normal or wetter years, to better prepare for future shortages. Meeting Texas’ agricultural water demands will likely require not only continued efficiency gains but also proactive policies, investment in new technologies, and coordinated management across regions.

Tian Su, Ph.D. ([email protected]) is an assistant research economist with the Texas Real Estate Research Center.