Dutch Hollow Lake
Sauk County, WisconsinOligotrophic
On the LakeGrade rubric, Dutch Hollow Lake pulls an A: clarity at 15.0 ft and 13 µg/L of phosphorus put it in the top bracket for Wisconsin. clarity and phosphorus rate similarly, so there is no obvious single lever to pull on watershed management.
Trophically, Dutch Hollow Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. A maximum depth of 38 ft puts Dutch Hollow Lake in the middle of Wisconsin's depth distribution. The lake's 172 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within Sauk County's 11 graded waters, Dutch Hollow Lake sits at rank 1, near the top of the local distribution.
Eurasian watermilfoil is established at Dutch Hollow Lake, which can dampen recreational access and pressure the native plant community. Walleye are documented at Dutch Hollow Lake, one of 2 fish species on record for the lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-29. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 15 ft down. Phosphorus level: 13.1 µg/L. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 15 ft | A |
| Phosphorus | 13.1 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 40 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 38 ft |
| Surface Area | 172 acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Dutch Hollow Lake (14-day solunar calendar)
→ Is it safe to eat fish from Dutch Hollow Lake? (mercury & PFAS guide)
→ Dutch Hollow Lake fishing regulations (limits, seasons, special rules)
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.457 m/yr | 6 |
| Phosphorus | → Stable | -0.01 µg/L/yr | 6 |
Location
County Ranking
Ranked #1 of 11 lakes in Sauk County
Nearby Lakes in Sauk County
More Wisconsin Lake Rankings
State Parks Near Dutch Hollow Lake
Other Grade A Lakes in Wisconsin
Washington County · Clarity: 11.8 ft
Washington County · Clarity: 12.6 ft
Walworth County · Clarity: 11 ft
Waukesha County · Clarity: 11.3 ft
Walworth County · Clarity: 20.2 ft
Kenosha County · Clarity: 10 ft
Oligotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1998. 5 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Reservoir Info (USACE NID)
Dutch Hollow Lake is a man-made reservoir impounded by the Dutch Hollow Lake (completed 1971), built primarily for recreation on the Dutch Hollow Creek; earth-type dam, 60 ft tall and 750 ft long.
- Surface area
- 125 ac
- Normal storage
- 1,250 ac-ft
- Max storage
- 5,500 ac-ft
- Drainage area
- 5 sq mi
- Hazard class
- Low
- Owner
- Dutch Hollow Lake Property Owners' Association, Inc.
Source: USACE National Inventory of Dams, NID ID WI00193 · Operator website
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-08-29
Monitoring stations: 1