Public-Supply Water Use in Kansas, 1990–2012

In brief. Public supply — water delivered through the systems of towns, rural water districts and similar suppliers — makes up about 10 percent of all reported water withdrawals in Kansas. From 1990 to 2012 it ranged from 121 billion gallons (1993) to 159 billion gallons (2012), rising and falling mainly with the weather. Six suppliers handled about half of it. By 2012 more than 99 percent was metered, and about 95 percent of Kansans were served by public supply.

Who regulates it

Every diversion for public supply on non-federal land in Kansas is regulated by one of two state agencies:

• Division of Water Resources (DWR), Kansas Department of Agriculture — most diversions, under municipal water rights. The Kansas Water Appropriation Act of 1945 requires a permit for any use but domestic. "Municipal" use means water delivered through a common distribution system run by a municipality, rural water district, public wholesale district, correctional facility, or anyone serving 10 or more homes or mobile homes.
• Kansas Water Office (KWO) — the Water Marketing Contract Program, set up in 1974 under the State Water Plan Storage Act, sells water from state-owned storage in federal reservoirs to towns and industry.

Water diverted under both includes water later sold to suppliers without rights of their own, so it is the whole amount eventually used for public supply.

In 2012 surface water came from streams, springs and lakes under 170 active DWR water rights and from 9 federal reservoirs through the KWO programme, mostly in the eastern half of the state. Groundwater came from about 2,600 wells, mainly along streams and over the High Plains aquifer.

Public water-supply points of diversion in 2012.

How the data are collected

Water-right holders must report their use to the DWR every year, and compliance has been excellent since penalties for not reporting began in 1988; the reports go into the DWR's Water Rights Information System. The KWO keeps monthly records of marketing-contract purchases, which are counted separately. About 92 percent of reported public-supply use was metered in 1990 and more than 99 percent in 2012.

Since 1987 the municipal reports also ask for wholesale purchases and sales, water sold for industry and livestock, sales to homes and businesses, and (since 1992) other metered public uses such as parks, pools and water treatment. Whatever was diverted or bought but not accounted for by these is "unaccounted for water." Reports also give the retail population served and the number of connections.

• About 700 reports a year come from holders of DWR water rights. About 600 are from suppliers serving retail customers year-round or wholesale districts; the rest are from non-community systems such as campgrounds, churches, hospitals and schools, which account for only about 0.1 percent of public-supply diversions.
• Since 2000 the DWR has also asked about 250 suppliers without water rights — those buying from others, and wholesale districts using KWO contracts — to report. They face no penalty, but nearly 80 percent reply each year.

In 2012 more than half of Kansas suppliers relied only on their own sources, more than a third bought all their water, and about 10 percent did both.

Withdrawals, 1990–2012

Surface water made up 52 to 61 percent of the yearly total. Water bought from federal reservoirs through KWO contracts grew from about 3 billion gallons in 1990 (less than 5 percent of surface water) to more than 7 billion in 2011 and 2012 (8 percent). Groundwater varied less than surface water.

In 2012 about 52 percent of all public-supply water, and 73 percent of the surface water, was treated and delivered by six suppliers in the most populous areas, largest first:

1. WaterOne (Water District 1 of Johnson County) — Kansas and Missouri Rivers
2. Wichita — Cheney Reservoir and wells
3. Kansas City (Board of Public Utilities) — Missouri River collector wells
4. Topeka — Kansas River
5. Olathe — Kansas River collector wells
6. Lawrence — Clinton Lake and Kansas River

Kansas grew steadily from nearly 2.5 million people in 1990 to almost 2.9 million in 2012. USGS estimates every five years put the share served by public supply at about 90 percent in 1990 and 1995, 93 percent in 2000, and 95 percent in 2005 and 2010; the rest got water elsewhere, such as private wells.

Dry years use more

The most water goes to public supply in the driest years, because people water outdoors more. The largest withdrawals came in years when statewide precipitation was under 30 inches; 2012, with less than 20 inches, had the most of all, and 1993, with nearly 40 inches, the least.

Water per person

Use per person is measured in gallons per capita per day (gpcd), computed each year since 1988 from the reports; the DWR uses it to administer water rights and the KWO for forecasting and conservation planning. For each supplier it counts residential and commercial sales, metered free uses and unaccounted-for water — so it reflects each system's own needs and losses — but leaves out water sold to industry and livestock, which varies hugely between suppliers.

Per capita use is highest in the drier west and lowest in the east, and usually lower in small towns than in big cities. So suppliers are compared within eight regions. Regions 1–5 are narrow because use climbs steeply from central Kansas to the western border; regions 6–8 are wider because use varies less. Mobile home parks are left out, and more small and medium systems (under 500 people, and 500–9,999) entered the count after 2000, mostly in regions 7 and 8.

Suppliers counted in 2012, by region: 1 — 16; 2 — 24; 3 — 20; 4 — 27; 5 — 48; 6 — 106; 7 — 334; 8 — 180.

The highest averages, and the biggest swings from year to year, are in regions 1–5, which are drier and have few suppliers; regions 7 and 8, wetter and with many suppliers, are lower and steadier.

• Region 1 (westernmost): from 228 gpcd in 2009 to 321 in 2002, averaging 274 gpcd over 1990–2012.
• Region 8 (easternmost): from 87 gpcd in 2009 to 108 in 1991, averaging 98 gpcd.

Nearly every region's highest averages came in 1990 and 1991, the last two years of a severe drought that began in 1988. Almost all rose sharply in 1994, 2000, 2002, 2006 and 2010–12, and almost all were lowest in 2009, the third year of above-normal precipitation in central and eastern Kansas.

Sources

• Kenny, J.F., 2014, Public-supply water use in Kansas, 1990–2012: U.S. Geological Survey Fact Sheet 2014–3116. https://pubs.usgs.gov/publication/fs20143116 — data from the Kansas Department of Agriculture's Division of Water Resources and the Kansas Water Office; supported in part by the Division of Water Resources and the Kansas State Water Plan Fund.
• The figures come from the fact sheet's PDF.
• Rewritten in hubnx's own words.