Lake Carter P Johnson
Sioux County, Nebraska17 acresView mapDirections
Clarity, phosphorus, and algae all sit in the cleanest band for this region.
↑ up from B at the last regrade
- Mesotrophic
- Impaired · Mercury
- #1 of 1 in the county
- Limited data
Lake Carter P Johnson in Sioux County, Nebraska has a water quality grade of A (Excellent). Water clarity: 8.3 ft visibility. Chlorophyll-a (algae): 3.4 µg/L. Surface area: 16.9 acres.
- Clarity
- 8.3 ft
- Area
- 17 acres
- Type
- Mesotrophic
- Chlorophyll-a
- 3.4 µg/L
- Trend
- ↓ Declining
Stays via Stay22
Stays near Lake Carter P Johnson
Compare lakeside cabins, hotels, and vacation rentals near Lake Carter P Johnson in Sioux County, Nebraska — 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.
Top-rated places to stay near Lake Carter P Johnson
Prices for Sep 11–13, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Nebraska’s top lakes →
Watch Lake Carter P Johnson’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Lake Carter P Johnson is a 17-acre mesotrophic lake in Sioux County, Nebraska. Water quality is graded A based on 1 sampling years through 2017. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, NDEE, last sampled 2017-09-26. Grade methodology: LakeQuality methodology.
What Lake Carter P Johnson is good for
From access and monitoring records, not editorial picks.
- Camping1 public campground nearby
Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The A is nutrients and algae, not a swimming clearance. Lake Carter P Johnson is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Water Quality Grade: A (Excellent)
Moderate clarity, visible to about 8.3 ft. Chlorophyll-a 3.4 µg/L. TSI 45. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.3 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 3.4 µg/L | Good |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 17 acres |
No bathymetric survey has been published for Lake Carter P Johnson, so its depth is not documented here.
Recreation & Access
Public campgrounds near Lake Carter P Johnson
- Soldier Creek Campground4.8 km
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Fishing Lake Carter P Johnson
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -2 m/yr | 5 |
| Chlorophyll-a | ↓ Declining | +0.16 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Lake Carter P Johnson is a man-made reservoir impounded by the Carter P Johnson Dam (completed 1935), built primarily for recreation on the Soldier Creek; earth-type dam, 35 ft tall and 480 ft long.
- Surface area
- 16.9 ac
- Normal storage
- 42.5 ac-ft
- Max storage
- 202.3 ac-ft
- Drainage area
- 52.7 sq mi
- Hazard class
- High
- Owner
- Nebraska Game & Parks Commission
Source: USACE National Inventory of Dams, NID ID NE01124 · Operator website
EPA Impairment Status
Lake Carter P Johnson is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit NE-WH1-L0200 · Official waterbody report · Matched by proximity (0.19 km)
County Ranking
Ranked #1 of 1 lakes in Sioux County
Nearby Lakes in Sioux County
Frequently asked questions about Lake Carter P Johnson
Where is Lake Carter P Johnson?
- Lake Carter P Johnson is a lake in Sioux County, Nebraska. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake Carter P Johnson?
- Lake Carter P Johnson in Sioux County, Nebraska has a water quality grade of A (Excellent). Water clarity: 8.3 ft visibility. Chlorophyll-a (algae): 3.4 µg/L. Surface area: 16.9 acres.
Is Lake Carter P Johnson safe to swim in?
- The A is nutrients and algae, not a swimming clearance. Lake Carter P Johnson is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Are there campgrounds on Lake Carter P Johnson?
- Lake Carter P Johnson has 1 public campground from USGS The National Map within 5 km, including Soldier Creek Campground. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Lake Carter P Johnson across LakeQuality
More Nebraska Lake Rankings
Other Grade A Lakes in Nebraska
Mesotrophic Lakes in Nebraska
Where this data comes from
48 measurements from 1 monitoring station, 2012–2017. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Nebraska Department of Environment and Energy
21NEB001_WQX48 samples · 2012–2017
Analytical methods
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 447.0 ~ EPA; Chlorophyll a and b in phytoplankton by HPLC/UV
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Public campgrounds from USGS The National Map Structures, within about 3 miles