Clark County, South Dakota — public water systems
At a glance
7 active public water systems are filed under Clark County, South Dakota in EPA's SDWIS records, together reporting 4,073 people served. The largest is Clark Rural Water System, which reports serving 2,325 people. All 7 are community water systems serving people where they live.
Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.
Active systems
7
Population served
4.1K
Community systems
7
Groundwater share
100%
How does Clark County compare with other South Dakota counties?
Clark County has the 18th-most active public water systems among the 73 counties listed for active South Dakota systems in EPA records; among the 48 with 3 or more systems, the median has 6. Its systems report 4,073 people served in total, the 34th-largest county figure in the state and 0.4% of the statewide total. The average system here reports serving 582 people, about 58% below the South Dakota average of 1,387. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.
Where does Clark County's drinking water come from?
By primary water source, Clark County's active systems draw on groundwater (4, 57%) and purchased groundwater (3, 43%). Overall, all rely mainly on groundwater (including purchased groundwater) and none on surface water, compared with 76% and 24% across South Dakota. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, Clark Rural Water System, draws primarily on groundwater.
What kinds of water systems operate in Clark County?
Clark County's active systems break down as 7 community systems (100%). A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. EPA lists their owner types as private (57%) and local government (43%).
Water systems in Clark County
🔒 Create a free account to export CSV| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | Clark Rural Water System | Clark + 3 more | 2,325 | Community | Groundwater |
| 2 | Clark | Clark | 1,148 | Community | Purchased groundwater |
| 3 | Willow Lake | Clark | 255 | Community | Purchased groundwater |
| 4 | Fordham Colony | Clark | 142 | Community | Groundwater |
| 5 | Collins Colony | Clark | 95 | Community | Groundwater |
| 6 | Shamrock Colony | Clark | 75 | Community | Groundwater |
| 7 | Garden City | Clark | 33 | Community | Purchased groundwater |
Also serving Clark County
These systems serve several counties, including Clark County. EPA lists another county first for them, so they are not included in the counts above.
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Sioux Rural Water System | Hamlin + 3 more | 4,280 | Community | Groundwater |
Clark County water systems: frequently asked questions
How many public water systems are in Clark County, South Dakota?
EPA's SDWIS records file 7 active public water systems under Clark County, South Dakota: 7 community systems (100%). At least 1 more system is listed under another county but also serve Clark County.
Who supplies drinking water in Clark County, SD?
The largest community water systems filed under Clark County are Clark Rural Water System (2,325 people served), Clark (1,148 people served) and Willow Lake (255 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.
Does Clark County's drinking water come from groundwater or surface water?
Of the 7 active public water systems in Clark County, all draw mainly on groundwater and none on surface water, counting purchased supplies. The largest system, Clark Rural Water System, uses groundwater.
Where can I find a water quality report for Clark County?
Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 7 community systems are filed under Clark County, so the report to look for is the one from the system that supplies your address.
How can I check violations for a water system in Clark County?
Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.
More South Dakota water systems
- All South Dakota public water systems· 699 active
- Union County· 8 systems
- Marshall County· 7 systems
- Bon Homme County· 7 systems
- Kingsbury County· 7 systems
- Moody County· 7 systems
- Beadle County· 7 systems
- How to find out who supplies your drinking water
- How to find and read your annual water quality report
About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Public water systems in Clark County, South Dakota”, https://aquacensus.com/water-systems/south-dakota/clark (data as of October 1, 2026).