Winnebago County, Iowa
7 ZIP codes · Avg score 63/100 · Grade C · Updated 2026-06-04
Covering 7 ZIP codes, Winnebago County falls in the average tier for tap water safety — violations appear in a meaningful share of areas, and the data suggests quality depends heavily on which specific part of the county a household sits in.
How Winnebago County Compares
How Winnebago County Compares
Winnebago County scores 4 points above the Iowa state average (59/100) and 5 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Winnebago County, Iowa
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.6 (asthma 9.9%, diabetes 11.6%)
Estimated additional annual cost per homeowner: $920, driven primarily by energy_code_gap
Infrastructure: 0.509% avg pipe failure probability, 100% of ZIPs at high risk
89.1% of homes built before 1978 (lead paint era)
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $920
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
5,718 housing units in Winnebago County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Winnebago County
Remediation costs are relatively manageable for most homeowners in Winnebago County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Winnebago County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Winnebago County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Lake Mills Municipal Water Department-south | 2,158 | 5 |
| 2 | Rocky Knoll Mhp | 49 | 5 |
| 3 | Crystal Lake Water Supply | 255 | 4 |
| 4 | Leland Water Supply | 249 | 4 |
| 5 | Forest City Water Supply | 4,285 | 1 |
11 total water systems serve Winnebago County.
All ZIP Codes in Winnebago County
7 ZIP codes tracked in Winnebago County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 50453 | Leland | 69 | C | 4 (1 health) | $163K |
| 2 | 50436 | Forest City | 68 | C | 1 | $164K |
| 3 | 50424 | Buffalo Center | 66 | C | 0 | $109K |
| 4 | 50450 | Lake Mills | 66 | C | 0 | $158K |
| 5 | 50465 | Rake | 66 | C | 0 | $34K |
| 6 | 50478 | Thompson | 66 | C | 0 | $94K |
| 7 | 50473 | Scarville | 40 | D | 0 | $141K |
Recommended Buyer Guides for Winnebago County
Where county records show a lead exceedance or pre-1978 housing concentration, lead-specific filters and test kits move toward the top of the list.
- Best Lead Paint Test Kits — 89.1% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Winnebago County, Iowa
Overview
Winnebago County in Iowa covers 7 ZIP codes with an average Home Safety Score of C (63/100).
2 of 7 ZIP codes have recorded EPA violations. 1 health-based violation have been documented.
← Back to Iowa water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.