Southwest Missouri faces a water crisis. If nothing is done, demand will exceed current supply by 2030. However, sufficient additional water to meet demand through 2060 appears to be available, and could be accessed at a relatively low cost. Whether doing so would impact the regions ecosystem is not known.

In the previous post, I reported that current stresses on water supply along the Missouri River depend primarily on human decisions about how to manage competing demands for the river’s water. The future effects of climate change are not yet known.

What about regions of the state that don’t depend on the Missouri River for their water supply? Are demands projected to exceed supply?

To answer that question, we must start by distinguishing between water resources and water supply. Water resources consist of the total water available in a region. Water supply is the amount of water that the infrastructure is capable of delivering.

Water resources consist of surface water and groundwater. Some regions of the state depend primarily on surface water. In fact, surface water supplies 8 of Missouri’s 10 largest cities, and 62% of the state’s total water consumption (44% from the Missouri River alone). Groundwater supplies about 38% of Missouri’s water consumption. Some regions, however, rely more heavily on groundwater, especially in the southern part of the state.

Figure 1. Southwest Missouri Counties Expected to Experience a Future Water Shortage. Source: Adapted from a map at Wikimedia Commons.

No region of the state is currently experiencing a sustained shortfall in water supply compared to demand. Perhaps the region most likely to experience one in the future is a 16 county area in Southwest Missouri. Figure 1 shows a map of the 16 counties.

The region has historically depended primarily on groundwater, as it is underlain by the Ozark Aquifer. Aquifer levels fluctuate depending on how much precipitation occurs to recharge them. In addition, over-pumping can deplete the water supply in a local region of the aquifer faster that water can flow in to replace it, causing a cone of depression. It can leave neighboring wells high and dry, but does not affect the whole aquifer. Severe over-pumping from multiple sources can deplete the entire aquifer, which is occurring in California.

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Figure 2. Missouri Population Density. Source: Tri-State Water Coalition.

The region’s constraints on water supply have occurred because of growth. Figure 2 is a map of population density in Missouri. It shows that Southwest Missouri is one of the more densely populated regions.

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Figure 3. Source: Tri-State Water Resource Coalition.

Figure 3 shows that from 1990-2000 the region was the fastest growing in the state. Between 2000 and 2010, the trend continued, with Christian County growing an astounding 43% and Taney County growing by 30%.

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Figure 4. Source: Tri-State Water Resource Coalition

The result has been over-pumping, and Figure 4 shows the results. In Southwest Missouri, most areas have experienced some decrease in the groundwater level. A few regions in Green County (the City of Springfield), Jasper County (the City of Joplin), and Stone and Taney Counties (the Branson area) have experienced cones of depression, dropping the water table more than 300 feet. The worst affected area is the large red area on the left side of the map. It is in Oklahoma, centered on Miami, OK.

Using a mid-level growth forecast, studies have calculated that current water resources will be overrun by demand by 2030. Even reducing demand through conservation would only meet needs through 2040.

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Figure 5. Projected Water Demand and Supply by 2060 in a Drought Year. Source: Tri-State Water Resource Coalition.

The region has significant surface water resources, however, and could supplement its water supply. Three significant reservoirs could supply water to the region: Stockton Lake, Table Rock Lake, and Lake Taneycomo. The first two are operated by the U.S. Army Corps of Engineers, and the latter is owned and operated by Empire District Electric Company. These organizations would have to approve the reallocation of water, but the water is there. Figure 5 shows projected available supply and demand if surface water resources were tapped. It would require the construction of pipelines and pumping stations, but the dams and reservoirs already exist.

Climate change is not projected to cause a decrease in precipitation in the region. The worst drought on record occurred in the 1950s, and if anything, the trend in precipitation has increased slightly since 1895. The temperature is projected to increase significantly, however. If increased temperature were to lead to less water reaching the aquifer to recharge it, then it could have implications for the regions water supply. But so far, those projections have not yet been calculated.

Unfortunately, none of the reports I contacted discuss the environmental impacts that the increasing demand for water will place on the ecosystem in the region. In fact, so far as I could tell, possible effects were not even considered. Will dropping water tables cause springs, creeks, and rivers to go dry? Will reallocation of the water from the regions reservoirs affect the health of the White and Osage Rivers? Will subsidence occur? These effects have occurred elsewhere, why Missouri would expect to be immune from them? But I just don’t know.

Thus, it appears that Southwest Missouri does face a water crisis. If nothing is done, demand will exceed current supply by 2030. However, sufficient additional water to meet demand through 2060 appears to be available, and could be accessed at a relatively low cost. Whether doing so would impact the regions ecosystem is not known.

Sources:

Missouri Department of Natural Resources. Springfield Plateau Groundwater Province. Downloaded 5/23/2017 from https://dnr.mo.gov/geology/wrc/groundwater/education/provinces/springfieldplatprovince.htm?/env/wrc/groundwater/education/provinces/springfieldplatprovince.htm.

State of Missouri and U.S. Army Corps of Engineers. 2012. Southwest Missouri Water Resource Study – Phase I. Downloaded 5/23/2017 from http://www.swl.usace.army.mil/Portals/50/docs/planningandenvironmental/Phase%20I%20-%20Southwest%20Missouri%20Water%20Study%20Final%20Report%20.pdf.

State of Missouri and U.S. Army Corps of Engineers. 2014. Southwest Missouri Water Resource Study – Phase II. Downloaded 5/23/2017 from http://tristatewater.org/wp-content/uploads/2014/11/Phase-II-FINAL-Southwest-Missouri-Supply-Availability-Report-Final_March_2014-from-Mike-Beezhold-9-16-14.pdf.

Tri-State Water Resource Coalition. 2015. Securing Water for Southwest Missouri. Downloaded 5/30/2017 from https://waterways.org/wordpress1/wp-content/uploads/2015/05/Securing-Water-for-Southwest-Missouris-Future.pdf.