Springbrook Lake
Guthrie County, Iowa12 acresView mapDirections
Nutrients and algae run above the regional average.
- Eutrophic
- #1 of 1 in the county
- Public access
Springbrook Lake in Guthrie County, Iowa has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 59 µg/L. Chlorophyll-a (algae): 22.9 µg/L. Surface area: 12 acres.
- Clarity
- 3 ft
- Typical in September
- 68°F
- Area
- 12 acres
- Type
- Eutrophic
- Phosphorus
- 59 µg/L
- Chlorophyll-a
- 22.9 µg/L
- Trend
- ↓ Declining
- Public access
- Yes
Stays via Stay22
Stays near Springbrook Lake
Compare lakeside cabins, hotels, and vacation rentals near Springbrook Lake in Guthrie County, Iowa — 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Springbrook Lake are listed below.
Top-rated places to stay near Springbrook Lake
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 Iowa’s top lakes →
Watch Springbrook Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Free interactive depth-contour map of Springbrook Lake, reaching a maximum surveyed depth of 20 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Springbrook Lake is a 12-acre productive, nutrient-rich eutrophic lake in Guthrie County, Iowa. Water quality is graded D based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-04. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyBacteria D
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.
Based on E. coli testing, Springbrook Lake frequently exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 20% of 5 samples across 2 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Iowa’s current beach and health-department advisories before swimming.
Water Quality Grade: D (Nutrient-rich)
Very murky, less than 3 ft of visibility. Phosphorus 59 µg/L. Chlorophyll-a 22.9 µg/L. TSI 62. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 ft | Not graded |
| Phosphorus | 59 µg/L | Poor |
| Chlorophyll-a (Algae) | 22.9 µg/L | Poor |
| Trophic State Index (TSI) | 62 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Temperature
Springbrook Lake typically sits around 68°F at the surface in September. Summer average is about 78°F. Usually warmest in Jul (about 81°F) and coldest in Sep (about 68°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 100 field readings (2010–2023) via the EPA Water Quality Portal. See the full Springbrook Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 12 acres |
| Public Access | Yes |
No bathymetric survey has been published for Springbrook Lake, so its depth is not documented here.
Fishing Springbrook Lake
Water Quality Trend: ↓ Declining
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.036 m/yr | 4 |
| Phosphorus | ↓ Declining | +69.9 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +7.46 µg/L/yr | 4 |
Reservoir Info (USACE NID)
Springbrook Lake is a man-made reservoir impounded by the Springbrook Lake Dam (completed 1934), built primarily for recreation on the TR-MIDDLE RACCOON RIVER; earth-type dam, 40 ft tall and 580 ft long.
- Surface area
- 12 ac
- Normal storage
- 58 ac-ft
- Max storage
- 187 ac-ft
- Drainage area
- 2.54 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA01345 · Operator website
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Springbrook Lake under Clean Water Act (NPDES) discharge permits.
- Dnr Springbrook State Park-Campground AreaGuthrie Center · 0.3 mi away · NPDES IA0075281
- Dnr Springbrook State ParkGuthrie Center · 0.7 mi away · NPDES IA0075272
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.
County Ranking
Ranked #1 of 1 lakes in Guthrie County
Nearby Lakes in Guthrie County
Frequently asked questions about Springbrook Lake
Where is Springbrook Lake?
- Springbrook Lake is a lake in Guthrie County, Iowa. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Springbrook Lake?
- Springbrook Lake in Guthrie County, Iowa has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 59 µg/L. Chlorophyll-a (algae): 22.9 µg/L. Surface area: 12 acres.
Is Springbrook Lake safe to swim in?
- Based on E. coli testing, Springbrook Lake frequently exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 20% of 5 samples across 2 seasons. That works out to a bacteria swim-safety grade of D — a historical summary of past testing, not a current reading. Springbrook Lake has a water quality grade of D (Nutrient-rich). Bacteria levels can spike quickly after heavy rain, so always check Iowa's current beach and health-department advisories before you swim.
What is the water temperature of Springbrook Lake?
- Springbrook Lake typically sits around 68°F at the surface in September, from 100 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
Explore Springbrook Lake across LakeQuality
More Iowa Lake Rankings
Other Grade D Lakes in Iowa
Eutrophic Lakes in Iowa
Where this data comes from
54 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Iowa DNR Surface Water Monitoring Data
21IOWA_WQX54 samples · 2021–2024
Analytical methods
- Unknown
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- In-Vitro Determination of Chlorophyll
- ISU modification of APHA 2130-B
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)