Jumbo Annex Lake
Logan County, Colorado100 acresView mapDirections
No nutrient or algae sampling on record from Colorado WQCD for this lake.
- Limited data
Jumbo Annex Lake in Logan County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Surface area: 100 acres.
Jumbo Annex Lake is a 100-acre lake in Logan County, Colorado.
Source: EPA Water Quality Portal sampling records, CDPHE, last sampled 2023-11-06. Methodology: how these readings are compared.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Jumbo Annex Lake is safe to swim in today is a call for the Water Quality Control Division of the Colorado Department of Public Health and Environment and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Jumbo Annex Lake
These are the measurements Colorado WQCD publishes for Jumbo Annex Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data.
Ask about Jumbo Annex Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
100 acres
No bathymetric survey has been published for Jumbo Annex Lake, so its depth is not documented here.
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Stays near Jumbo Annex Lake
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Fishing Jumbo Annex Lake
Reservoir Info (USACE NID)
Jumbo Annex Lake is a man-made reservoir impounded by the Jumbo (completed 1977), built primarily for fish and wildlife pond on the South Platte River-Tr; earth-type dam, 38 ft tall and 1,900 ft long.
- Surface area
- 100 ac
- Normal storage
- 950 ac-ft
- Max storage
- 1,450 ac-ft
- Drainage area
- 1 sq mi
- Hazard class
- Low
- Owner
- COLORADO PARKS AND WILDLIFE
Source: USACE National Inventory of Dams, NID ID CO00382 · Operator website · Matched by proximity (0.08 km)
Nearby Lakes in Logan County
Frequently asked questions about Jumbo Annex Lake
Where is Jumbo Annex Lake?
- Jumbo Annex Lake is a lake in Logan County, Colorado. Its water-quality measurements are published by Colorado WQCD and shown on this page as reported.
What is the water quality of Jumbo Annex Lake?
- Jumbo Annex Lake in Logan County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Surface area: 100 acres.
Is Jumbo Annex Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
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Where this data comes from
8 measurements from 1 monitoring station, 2022–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Colorado Dept. of Public Health & Environment-WQCD
21COL001_WQX8 samples · 2022–2023
Analytical methods
- Secchi disk depth measurement
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Nitrogen in Water by Pyrolysis Detection
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.