Lamb Lake
Johnson County, Indiana56 acresView mapDirections
IDEM publishes the water-quality measurements for Lamb Lake. Here is what has been measured.
- Limited data
Lamb Lake in Johnson County, Indiana has water-quality measurements published by IDEM, shown here as reported. Water clarity: 7.2 ft visibility. Surface area: 56.3 acres.
Lamb Lake is a 56-acre lake in Johnson County, Indiana. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, IDEM, last sampled 2023-07-11. Methodology: how these readings are compared.
Lamb Lake covers about 56 acres in Johnson County. For a place on the water, look through cabin and lake-house rentals near Lamb Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Lamb Lake is safe to swim in today is a call for the Indiana Department of Environmental Management and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lamb Lake
These are the measurements IDEM publishes for Lamb Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 7.2 ft. TSI 49.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 7.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 49 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Lamb Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
56 acres
No bathymetric survey has been published for Lamb Lake, so its depth is not documented here.
Stays via Stay22
Stays near Lamb Lake
Compare lakeside cabins, hotels, and vacation rentals near Lamb Lake in Johnson County, Indiana — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
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Fishing Lamb Lake
Water Quality Trend: Worsening
Based on 5 years of monitoring (2020–2024).
Water clarity
Stable5 years
Phosphorus
Worsening+10.5 µg/L/yr5 years
Chlorophyll-a
Worsening+1.1 µg/L/yr5 years
Reservoir Info (USACE NID)
Lamb Lake is a man-made reservoir impounded by the Lamb Lake Dam (completed 1937), built primarily for recreation on the UNNAMED TRIBUTARY BEAR CREEK; earth-type dam, 45 ft tall and 860 ft long.
- Surface area
- 56.3 ac
- Normal storage
- 1,600 ac-ft
- Max storage
- 1,600 ac-ft
- Drainage area
- 3.1 sq mi
- Hazard class
- High
- Owner
- THOMAS JOHNSON
Source: USACE National Inventory of Dams, NID ID IN00338 · Operator website
Regulated Pollution Sources Nearby
12 EPA-permitted facilities operate within about 5 miles of Lamb Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Trafalgar WwtpTrafalgar · 4.7 mi away · NPDES IN0040681Recent violation
- Riviera Club RenovationsIndianapolis · 1.1 mi away · NPDES INR10N641
- Brown County Water Utility Inc Phase Ii Cr 400 W, 650 S & 450 W Water Main ExteTrafalgar · 1.2 mi away · NPDES INRA00857
- Transportation And Maintenance FacilityTrafalgar · 3.1 mi away · NPDES INRA04331
- Indian Creek Elementary SchoolTrafalgar · 3.3 mi away · NPDES INR10J806
- Nhj School Corporation New Facilities And RenovationsTrafalgar · 3.5 mi away · NPDES INRA08253
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Johnson County
Frequently asked questions about Lamb Lake
Where is Lamb Lake?
- Lamb Lake is a lake in Johnson County, Indiana. Its water-quality measurements are published by IDEM and shown on this page as reported.
What is the water quality of Lamb Lake?
- Lamb Lake in Johnson County, Indiana has water-quality measurements published by IDEM, shown here as reported. Water clarity: 7.2 ft visibility. Surface area: 56.3 acres.
Is Lamb Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Lamb Lake across LakeQuality
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Where this data comes from
3 measurements from 1 monitoring station, 2021–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North American Lake Management Society
NALMS3 samples · 2021–2023
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)