Dale Maffitt Reservoir
Dallas County, WisconsinMesotrophic
Dale Maffitt Reservoir is a 230-acre mesotrophic lake in Dallas County, IA. Water quality is graded B based on 2 sampling years through 2022. Compared to the 1 other monitored lakes in Dallas County, Dale Maffitt Reservoir ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2022-09-07. Grade methodology: LakeGrade methodology.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Moderate clarity, visible to about 9.8 ft. Chlorophyll-a: 2.5 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9.8 ft | C |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 2.5 µg/L | A |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 230 acres |
Location
County Ranking
Ranked #1 of 2 lakes in Dallas County
Cleaner Lakes Within 30 Miles
Dale Maffitt Reservoir holds Grade B. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in Dallas County
More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Dale Maffitt Reservoir is a man-made reservoir impounded by the Maffitt Reservoir Dam (completed 1944), built primarily for water supply on the TR-RACCOON RIVER; earth-type dam, 79 ft tall and 1,800 ft long.
- Surface area
- 230 ac
- Normal storage
- 5,200 ac-ft
- Max storage
- 6,700 ac-ft
- Drainage area
- 1.41 sq mi
- Hazard class
- High
- Owner
- Des Moines Water Works
Source: USACE National Inventory of Dams, NID ID IA01338 · Operator website
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2022-09-07
Monitoring stations: 1