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Federal water data

County water report

Minnehaha County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Minnehaha County, South Dakota.

Water grade

A

Water score

70.4

State rank

#29

of 63

Health violations

2

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

34

2,989 recent measurements

Live streamflow

51%

BIG SIOUX R AT NORTH CLIFF AVE AT SIOUX FALLS,SD

Water at a glance

Key Water Indicators for Minnehaha County

EPA SDWIS

Safety Grade

A

Score: 70.4 / 100

EPA SDWIS

Active Violations

2

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

51% of mean

BIG SIOUX R AT NORTH CLIFF AVE AT SIOUX FALLS,SD

EPA WQP

Monitoring Sites

34

2,989 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

A

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

70.4/100

Health violations

2

Health-based violations

Violations per 100K served

0.8

Population-normalized SDWIS rate

Data center water stress

Minnehaha County has 2 facilities in the DCWSI dataset.

ByCounty's DCWSI ranks this county #126 nationally by combining its water score with mapped data center density.

DCWSIThe Data Center Water Stress Index: 60% the county's water-system stress plus 40% how concentrated data centers already are, scored 0-100. Higher means data-center density and water pressure overlap more here.

60.2

0-100 index

Facility count

2

45.0 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

+20.4

Compared with US county median

Mapped facilities

  • ADP South Dakota

    Facility details limited

    OSM

  • TierPoint Sioux Falls West Data Center

    Sioux Falls

    OSM
See the Minnehaha County data-center reportReview methodology

Data Center Water Budget Calculator

Estimate daily water use for a hypothetical facility in Minnehaha County.

1 MW1,000 MW
40%100%
799K gallons/dayHigh Impact

Your facility would use 55.2% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

55.2% of county industrial baseline0.65 Mgal/day remaining headroom

Based on USGS 2020 water-use data and EPA-standard cooling intensity constants. Not a substitute for site-specific water rights analysis.

Editorial analysis

Understanding Minnehaha County’s Water

Drinking Water Quality Overview

EPA SDWIS

Minnehaha County earns an A grade for drinking water quality, scoring 70.4 out of 100. Over the past five years, EPA SDWIS records 2 health-based violations — a small cluster that warrants attention.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T13:30:00.000-05:00) puts BIG SIOUX R at 414.0 cfs — well below its long-term average at 51% of mean — low-flow conditions worth noting for water-dependent ecosystems. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Minnehaha County has moderate coverage with 34 active monitoring sites with 2,989 recent measurements on record. Predominant monitoring categories include physical and nutrient. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Minnehaha County

Water Verdict

Minnehaha County, South Dakota receives a good water quality assessment with a grade of A and a score of 70.4 out of 100. While the water supply is generally safe, occasional monitoring gaps or minor contaminant detections may occur. The county's primary USGS gauge drains roughly 4,662 square miles of upstream watershed, giving local source waters a regional footprint. At the most recent USGS reading, local streamflow was below its historical mean at 50.9% — worth watching in drier seasons.

Violation Context

EPA SDWIS records for Minnehaha County, South Dakota show 2 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 0.8 violations per 100,000 people served, this rate is relatively low compared to many U.S. counties. For independent context, 2,989 water-quality monitoring results have been recorded across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Tap water in Minnehaha County earns a Grade A overall with a small number of isolated health violations in the recent record. Minnehaha County's drinking-water compliance score is 70.4 out of 100. The violation rate for Minnehaha County is 0.8 per 100,000 people served. These violations were likely resolved quickly; Grade A reflects a strong multi-year compliance trend. Reviewing the most recent Consumer Confidence Report will show exactly which systems were affected and what corrective action was taken. With 34 active water-quality monitoring sites in Minnehaha County, data coverage is strong. A pipeline streamflow snapshot from the BIG SIOUX R gauge is also available on this page.

Regional Context

Minnehaha County has better water quality than the average county in South Dakota. Its water score is 13.6 points higher than the state average, indicating stronger water system performance relative to neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Minnehaha County's water environment

Official EPA Resources for Minnehaha County

EPA How's My Waterway

Interactive watershed health data for Minnehaha County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Minnehaha County

Consumer Confidence Reports (SD)

Annual water quality reports from utilities in South Dakota

Past 5 years

Water Quality Monitoring

Monitoring Sites

34

Active in the past 5 years

Measurements Recorded

3.0K

2,989 total readings

Most Measured

  • Physical
  • Nutrient
  • Microbiological

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

414cfs

May 14, 6:30 PM UTC

vs Long-Term Average

51%

Well below typical

Primary Streamgage

BIG SIOUX R AT NORTH CLIFF AVE AT SIOUX FALLS,SD

USGS site
06482020
Drainage area
4,662 sq mi
Long-term mean
813 cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

Free tool

Estimate Your Water Costs

Water Cost Estimate

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Minnehaha County:C — Moderate

Some violations or watershed impairment detected.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

Try the full calculator →

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Frequently Asked Questions

What is the water quality in Minnehaha County, South Dakota?
Minnehaha County, South Dakota has a drinking-water quality grade of A with a score of 70.4/100, based on EPA SDWIS compliance data. The county has 2 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.
Are there any water violations in Minnehaha County?
Minnehaha County has 2 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.
How much water-quality monitoring happens in Minnehaha County?
EPA's Water Quality Portal records 2,989 measurements from 34 monitoring sites in Minnehaha County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Microbiological. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.
What's happening with rivers in Minnehaha County right now?
Minnehaha County's primary USGS streamgage on the BIG SIOUX R has a pipeline snapshot of 414 cubic feet per second — 51% of the long-term mean of 813.4 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.
How does Minnehaha County water compare to the South Dakota average?
Minnehaha County's SDWIS water quality score of 70.4/100 is higher than the South Dakota state average of 56.8. The average water quality grade across South Dakota is D, based on data from 63 counties with available SDWIS data.
Is tap water safe to drink in Minnehaha County?
Based on EPA SDWIS data, Minnehaha County has a water quality grade of A (70.4/100). This indicates good to excellent water quality with strong SDWIS compliance. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).
Does Minnehaha County have clean drinking water?
Minnehaha County has 2 health-based drinking water violations according to EPA records. With a water quality score of 70.4/100 and grade A, the county's drinking water has had some compliance issues but continues to be monitored. Note: drinking-water compliance speaks to the public water system, not necessarily to the watershed itself — check the Watershed Health zone for ATTAINS §303(d) data.
How does Minnehaha County rank for water quality in South Dakota?
Minnehaha County ranks #29 out of 63 counties in South Dakota by SDWIS water quality score (1 = best). With a score of 70.4/100, it falls in the middle third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Codington County

South Dakota

B

64.1

Water score

Clay County

South Dakota

C

57.7

Water score

Brookings County

South Dakota

C

57.2

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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