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Columbia County, Wisconsin — public water systems

At a glance

140 active public water systems are filed under Columbia County, Wisconsin in EPA's SDWIS records, together reporting 64,780 people served. The largest is Portage Waterworks, which reports serving 10,437 people. 26 are community water systems serving people where they live; the other 114 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.

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

Active systems

140

Population served

64.8K

Community systems

26

Groundwater share

100%

How does Columbia County compare with other Wisconsin counties?

Columbia County has the 37th-most active public water systems among the 90 counties listed for active Wisconsin systems in EPA records; among the 74 with 3 or more systems, the median has 140. Its systems report 64,780 people served in total, the 21st-largest county figure in the state and 1.2% of the statewide total. The average system here reports serving 463 people, roughly in line with the Wisconsin average of 469. 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 Columbia County's drinking water come from?

By primary water source, Columbia County's active systems draw on groundwater (140, 100%). Overall, all rely mainly on groundwater (including purchased groundwater) and none on surface water, compared with 99% and 0.6% across Wisconsin. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, Portage Waterworks, draws primarily on groundwater.

What kinds of water systems operate in Columbia County?

Columbia County's active systems break down as 26 community systems (19%), 20 non-transient non-community systems (14%) and 94 transient non-community systems (67%). 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. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. EPA lists their owner types as private (81%), local government (11%) and state government (7.1%).

The 50 largest water systems in Columbia County

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Active public water systems in Columbia County, Wisconsin
#Water systemCountyPopulation servedTypeSource
1Portage WaterworksColumbia10,437CommunityGroundwater
2Columbus UtilitiesColumbia5,173CommunityGroundwater
3Wi Dot Rest Area 12 Dekorra West BoundColumbia3,255Transient non-communityGroundwater
4Wisconsin Dells WaterworksColumbia3,232CommunityGroundwater
5Lodi WaterworksColumbia3,146CommunityGroundwater
6Poynette WaterworksColumbia2,520CommunityGroundwater
7Wi Dot Rest Area 11 Dekorra East BoundColumbia2,505Transient non-communityGroundwater
8Pardeeville WaterworksColumbia2,151CommunityGroundwater
9Harmony Grove San DistColumbia1,950CommunityGroundwater
10Randolph Water DeptColumbia1,800CommunityGroundwater
11Fall River WaterworksColumbia1,793CommunityGroundwater
12Rio WaterworksColumbia1,095CommunityGroundwater
13Loves Travel Stops PoynetteColumbia1,051Non-transient non-communityGroundwater
14Cascade Mtn Ski - 93 Well MainColumbia967Transient non-communityGroundwater
15Arlington WaterworksColumbia946CommunityGroundwater
16Petro Travel Plaza #403Columbia915Non-transient non-communityGroundwater
17Pride of America Campground - Main System Wells 1 2 and 4Columbia912Transient non-communityGroundwater
18Mcdonalds Restaurant PoynetteColumbia845Non-transient non-communityGroundwater
19Northpoint Plaza BpColumbia809Transient non-communityGroundwater
20Wyocena WaterworksColumbia768CommunityGroundwater
21Cambria WaterworksColumbia767CommunityGroundwater
22Crystal Lake Rv Resort LLCColumbia725CommunityGroundwater
23All Stop PlazaColumbia718Transient non-communityGroundwater
24Saddle Ridge EstatesColumbia700CommunityGroundwater
25Luckys Bar & Grille on the LakeColumbia606Transient non-communityGroundwater
26Zion Ev Lutheran Church of LeedsColumbia507Transient non-communityGroundwater
27Wi Dot Wayside 17 West PointColumbia500Transient non-communityGroundwater
28Sunset HarborColumbia410Transient non-communityGroundwater
29Cascade Mtn Ski - Daisy Restaurant WellColumbia400Transient non-communityGroundwater
30Friesland WaterworksColumbia345CommunityGroundwater
31Silver Springs Campsites Office and PoolColumbia320Transient non-communityGroundwater
32Silver Springs Campsites Hilltop WellColumbia320Transient non-communityGroundwater
33Cimarolis Supper ClubColumbia316Transient non-communityGroundwater
34Camp Wawbeek Nature Center - Main WellColumbia306Transient non-communityGroundwater
35Camp Wawbeek - Respite Camp Rec CenterColumbia306Transient non-communityGroundwater
36Hookers ResortColumbia306Transient non-communityGroundwater
37Camp Wawbeek - Respite Camp LodgeColumbia306Transient non-communityGroundwater
38Remis Thirsty MooseColumbia305Transient non-communityGroundwater
39Indian Trails Campground - East HillColumbia300Transient non-communityGroundwater
40Indian Trails Campground - Bath HouseColumbia300Transient non-communityGroundwater
41Bethlehem Lutheran ChurchColumbia252Transient non-communityGroundwater
42Lake Wisconsin Country ClubColumbia250Transient non-communityGroundwater
43Trienda Holdings LLCColumbia240Non-transient non-communityGroundwater
44Fitzs on the LakeColumbia215Transient non-communityGroundwater
45Triple Play Sports Bar & GrillColumbia208Transient non-communityGroundwater
46Indian Trails Campground - RestaurantColumbia206Transient non-communityGroundwater
47Subway Sandwiches - PoynetteColumbia205Transient non-communityGroundwater
48Anchor at Lakeside Bar & GrillColumbia204Transient non-communityGroundwater
49Interstate Easy StopColumbia203Transient non-communityGroundwater
50Portage One StopColumbia203Transient non-communityGroundwater

All other water systems in Columbia County (90)

The remaining active systems filed under Columbia County, largest first, with the population each reports serving.

Columbia County water systems: frequently asked questions

How many public water systems are in Columbia County, Wisconsin?

EPA's SDWIS records file 140 active public water systems under Columbia County, Wisconsin: 26 community systems (19%), 20 non-transient non-community systems (14%) and 94 transient non-community systems (67%).

Who supplies drinking water in Columbia County, WI?

The largest community water systems filed under Columbia County are Portage Waterworks (10,437 people served), Columbus Utilities (5,173 people served) and Wisconsin Dells Waterworks (3,232 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 Columbia County's drinking water come from groundwater or surface water?

Of the 140 active public water systems in Columbia County, all draw mainly on groundwater and none on surface water, counting purchased supplies. The largest system, Portage Waterworks, uses groundwater.

Where can I find a water quality report for Columbia 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. 26 community systems are filed under Columbia 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 Columbia 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 Wisconsin water systems

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 Columbia County, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/columbia (data as of October 1, 2026).