Costilla County, Colorado — public water systems

At a glance

12 active public water systems are filed under Costilla County, Colorado in EPA's SDWIS records, together reporting 2,872 people served. The largest is San Luis Wsd, which reports serving 629 people. 8 are community water systems serving people where they live; the other 4 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.

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

Active systems

Population served

2.9K

Community systems

Groundwater share

100%

How does Costilla County compare with other Colorado counties?

Costilla County has the 45th-most active public water systems among the 113 counties listed for active Colorado systems in EPA records; among the 65 with 3 or more systems, the median has 18. Its systems report 2,872 people served in total, the 58th-largest county figure in the state and less than 0.1% of the statewide total. The average system here reports serving 239 people, well below the Colorado average of 3,400. 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 Costilla County's drinking water come from?

By primary water source, Costilla County's active systems draw on groundwater (12, 100%). Overall, all rely mainly on groundwater (including purchased groundwater) and none on surface water, compared with 74% and 26% across Colorado. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, San Luis Wsd, draws primarily on groundwater.

What kinds of water systems operate in Costilla County?

Costilla County's active systems break down as 8 community systems (67%), 3 non-transient non-community systems (25%) and 1 transient non-community systems (8.3%). 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 local government (58%) and private (42%).

Water systems in Costilla County

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Active public water systems in Costilla County, Colorado
#	Water system	County	Population served	Type	Source
1	San Luis Wsd	Costilla	629	Community	Groundwater
2	Costilla County Ws	Costilla	561	Community	Groundwater
3	Ft Garland Wsd	Costilla	477	Community	Groundwater
4	Blanca Town of	Costilla	469	Community	Groundwater
5	Sierra Grande School District	Costilla	304	Non-transient non-community	Groundwater
6	Blanca Ft Garland Md	Costilla	108	Transient non-community	Groundwater
7	Garcia Domestic Wua	Costilla	100	Community	Groundwater
8	Trinchera Property Management Inc.	Costilla	55	Non-transient non-community	Groundwater
9	Blanca Forestry Products	Costilla	50	Non-transient non-community	Groundwater
10	Viejo San Acacio	Costilla	45	Community	Groundwater
11	San Acacio Domestic Wa	Costilla	40	Community	Groundwater
12	Lake Sanchez Estates	Costilla	34	Community	Groundwater

Costilla County water systems: frequently asked questions

How many public water systems are in Costilla County, Colorado?

EPA's SDWIS records file 12 active public water systems under Costilla County, Colorado: 8 community systems (67%), 3 non-transient non-community systems (25%) and 1 transient non-community systems (8.3%).

Who supplies drinking water in Costilla County, CO?

The largest community water systems filed under Costilla County are San Luis Wsd (629 people served), Costilla County Ws (561 people served) and Ft Garland Wsd (477 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 Costilla County's drinking water come from groundwater or surface water?

Of the 12 active public water systems in Costilla County, all draw mainly on groundwater and none on surface water, counting purchased supplies. The largest system, San Luis Wsd, uses groundwater.

Where can I find a water quality report for Costilla 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. 8 community systems are filed under Costilla 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 Costilla 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 Colorado 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 Costilla County, Colorado”, https://aquacensus.com/water-systems/colorado/costilla (data as of October 1, 2026).