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LakeQuality

Pasisades Reservoir

Bonneville County, IdahoView mapDirections

Idaho DEQ publishes the water-quality measurements for Pasisades Reservoir. Here is what has been measured.

Clarity
10.5 ft
Typical for Idaho
Secchi · sampled 2023
Phosphorus
15 µg/L
Less phosphorus than most
Measured by Idaho DEQ
Chlorophyll-a
2.9 µg/L
Typical for Idaho
Measured by Idaho DEQ
Type
Mesotrophic
Trophic class
Trend
Stable
13 years of samples
  • Mesotrophic
  • Public access
  • Limited data

Pasisades Reservoir in Bonneville County, Idaho has water-quality measurements published by Idaho DEQ, shown here as reported. Water clarity: 10.5 ft visibility. Phosphorus: 15 µg/L. Chlorophyll-a (algae): 2.9 µg/L.

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Pasisades Reservoir is a mesotrophic lake in Bonneville County, Idaho. Water clarity is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 5 other monitored lakes in Bonneville County, Pasisades Reservoir ranks #3 for water quality.

Source: EPA Water Quality Portal sampling records, IDEQ, last sampled 2023-06-29. Methodology: how these readings are compared.

What Pasisades Reservoir is good for

From access and monitoring records, not editorial picks.

  • Clear water10.5 ft of visibility
  • Boat launch1 documented ramp

Swimming conditions

Readings only

Limited data

Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Pasisades Reservoir is safe to swim in today is a call for the Idaho Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Pasisades Reservoir

These are the measurements Idaho DEQ publishes for Pasisades Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

Good clarity, visible to about 10.5 ft. Phosphorus 15 µg/L. Chlorophyll-a 2.9 µg/L. TSI 42.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)10.5ftMeasured, not scored

How deep a black-and-white disk stays visible from the surface. Higher is clearer.

Total phosphorus15µg/LGood
GoodFairPoor
Chlorophyll-a (algae)2.9µg/LFair
GoodFairPoor
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.42Mesotrophic
OligotrophicMesotrophicEutrophicHypereutrophic

Moderate nutrients, good water quality

Ask about Pasisades Reservoir

Answers come straight from the public measurements and survey records on this page.

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Blowout CanyonPublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Stays via Stay22

Stays near Pasisades Reservoir

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Top-rated places to stay near Pasisades Reservoir

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Fishing Pasisades Reservoir

Based on 13 years of monitoring (2012–2024).

  • Water clarity

    Worsening

    13 years

  • Phosphorus

    Improving

    -1.41 µg/L/yr13 years

  • Chlorophyll-a

    Stable

    +0.03 µg/L/yr12 years

See year-by-year chart →

Nearby Lakes in Bonneville County

Frequently asked questions about Pasisades Reservoir

Where is Pasisades Reservoir?

Pasisades Reservoir is a lake in Bonneville County, Idaho. Its water-quality measurements are published by Idaho DEQ and shown on this page as reported.

What is the water quality of Pasisades Reservoir?

Pasisades Reservoir in Bonneville County, Idaho has water-quality measurements published by Idaho DEQ, shown here as reported. Water clarity: 10.5 ft visibility. Phosphorus: 15 µg/L. Chlorophyll-a (algae): 2.9 µg/L.

Measurements on this page ↑

Is Pasisades Reservoir safe to swim in?

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Swimming on this page ↑

Are there boat ramps on Pasisades Reservoir?

Pasisades Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Blowout Canyon. Public access is listed as yes.

Access on this page ↑

Can I fish at Pasisades Reservoir?

Pasisades Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Idaho's fish and wildlife agency, so check its current regulations before you go.

Access on this page ↑

Where this data comes from

20 measurements from 1 monitoring station, 2013–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Bureau of Reclamation1119USBR_WQX20 samples · 2013–2023

Analytical methods

  • Depth, Secchi disk depth
  • Zebra/Quagga Mussel APHA 10200G Modified
  • Phosphorus by Single Reagent Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
  • Turbidity by Nephelometry
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

Named boat-access points from the USGS National Boat Ramps inventory