How many public water systems are in South Dakota?

South Dakota has 706 active public water systems in EPA SDWIS records, including 510 community water systems. Together they report serving 967K people.

What is the largest water system in South Dakota?

Sioux Falls is the largest active public water system in South Dakota, serving a reported 216,462 people.

Does South Dakota rely more on groundwater or surface water?

76.5% of South Dakota's active public water systems draw primarily on groundwater and 23.5% on surface water (including purchased supplies).

South Dakota public water systems

706 active systems regulated under the Safe Drinking Water Act, serving a reported 967K people across 71 counties.

Dataset updated July 2026 . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

706

Population served

967K

Community systems

510

Groundwater share

76.5%

System types in South Dakota

510

Community water system

Non-transient non-community water system

180

Transient non-community water system

Largest water systems in South Dakota

The largest active public water systems in South Dakota by population served
#	Water system	County	Population served	Type	Source
1	Sioux Falls	Minnehaha	216,462	Community	Surface water
2	Rapid City	Pennington	72,009	Community	Surface water
3	Aberdeen	Brown	27,989	Community	Surface water
4	Brookings Municipal Utilities	Brookings	23,377	Community	Groundwater
5	Watertown Municipal Utilities	Codington	23,230	Community	Groundwater
6	Web Water Development Association	Walworth	20,750	Community	Surface water
7	Mitchell	Davison	15,651	Community	Purchased surface water
8	Yankton	Yankton	15,411	Community	Groundwater
9	Huron	Beadle	14,263	Community	Purchased surface water
10	Pierre	Hughes	14,091	Community	Surface water
11	Box Elder	Pennington	14,000	Community	Groundwater
12	Minnehaha Community Water Corp	Minnehaha	13,435	Community	Groundwater
13	By Water District	Bon Homme	13,320	Community	Surface water
14	Spearfish	Lawrence	12,193	Community	Groundwater
15	Mid-Dakota Rural Water	Hughes	11,833	Community	Surface water
16	Vermillion	Clay	11,695	Community	Groundwater
17	Rapid Valley Sanitary District	Pennington	11,408	Community	Surface water
18	Brandon	Minnehaha	11,048	Community	Groundwater
19	Harrisburg	Lincoln	10,297	Community	Purchased groundwater
20	Ellsworth Afb	Pennington	9,100	Community	Purchased surface water
21	Pine Ridge Water System	—	7,482	Community	Groundwater
22	Tea	Lincoln	7,381	Community	Purchased groundwater
23	Sturgis	Meade	7,020	Community	Groundwater
24	Kyle Water System	—	6,526	Community	Purchased surface water
25	Kingbrook I Rural Water System	Brookings	6,455	Community	Purchased groundwater

By county

Pennington156 systems Lawrence73 systems Meade56 systems Custer51 systems Brown21 systems Minnehaha15 systems Fall River13 systems Brookings12 systems Roberts11 systems Butte10 systems Spink10 systems Lincoln9 systems Yankton9 systems Union8 systems Clark7 systems Bon Homme7 systems Edmunds7 systems Moody7 systems Marshall7 systems Kingsbury7 systems Codington6 systems Day6 systems Turner6 systems Hughes6 systems McCook6 systems Charles Mix6 systems Hamlin6 systems Beadle6 systems Faulk6 systems Douglas5 systems Dewey5 systems Grant5 systems Lake5 systems Sanborn5 systems Aurora4 systems Gregory4 systems Potter4 systems Davison4 systems Clay4 systems Hutchinson4 systems Walworth4 systems Perkins3 systems Lyman3 systems Corson3 systems Brule3 systems Hanson3 systems Hand3 systems Tripp3 systems Stanley3 systems

Wright2 systems

Shannon2 systems

Jackson2 systems

McPherson2 systems

Haakon2 systems

Jerauld2 systems

Deuel2 systems

Campbell2 systems

Miner2 systems

Houston1 systems

Murray1 systems

Williams1 systems

Buffalo1 systems

Jones1 systems

Sully1 systems

Ziebach1 systems

Bennett1 systems

Mellette1 systems

Harding1 systems

Hyde1 systems

Van Buren1 systems

Kalamazoo1 systems