Henry Hagg Lake
Washington County, Oregon1,157 acresView mapDirections
Oregon DEQ publishes the water-quality measurements for Henry Hagg Lake. Here is what has been measured.
- Oligotrophic
- Public access
- Limited data
Henry Hagg Lake in Washington County, Oregon has water-quality measurements published by Oregon DEQ, shown here as reported. Chlorophyll-a (algae): 1.5 µg/L. Surface area: 1157 acres.
Henry Hagg Lake is a 1,157-acre cold, clear oligotrophic lake in Washington County, Oregon. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 1 other monitored lakes in Washington County, Henry Hagg Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Oregon DEQ, last sampled 2025-10-14. Methodology: how these readings are compared.
Henry Hagg Lake covers about 1,200 acres in Washington County. It has one public boat landing. For a place on the water, look through cabin and lake-house rentals near Henry Hagg Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Henry Hagg Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Big water1,157 acres
Swimming conditions
Readings onlyLimited 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 Henry Hagg Lake is safe to swim in today is a call for the Oregon Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Henry Hagg Lake
These are the measurements Oregon DEQ publishes for Henry Hagg 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. Chlorophyll-a 1.5 µg/L. TSI 35.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading 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) | 1.5µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 35 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Henry Hagg Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
1,157 acres
Public access
Yes
Listed by Oregon DEQ
No bathymetric survey has been published for Henry Hagg Lake, so its depth is not documented here.
Recreation & Access
- Henry Hagg LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Henry Hagg Lake
Compare lakeside cabins, hotels, and vacation rentals near Henry Hagg Lake in Washington County, Oregon — 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 Henry Hagg Lake
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Fishing Henry Hagg Lake
Water quality readings over time
2 seasons of samples on record (2024–2025). Calling a direction takes at least 4 years of the same measurement.
Chlorophyll-a
Improving-0.2 µg/L/yr2 years
Reservoir Info (USACE NID)
Henry Hagg Lake is a man-made reservoir impounded by the Scoggins Dam (completed 1975), built primarily for irrigation on the Scoggins Creek; earth-type dam, 151 ft tall and 2,700 ft long.
- Surface area
- 1,157 ac
- Normal storage
- 59,910 ac-ft
- Max storage
- 60,000 ac-ft
- Drainage area
- 38.57 sq mi
- Hazard class
- High
- Owner
- BUREAU OF RECLAMATION
All listed purposes: Irrigation;Water Supply.
Source: USACE National Inventory of Dams, NID ID OR00685 · Operator website
Nearby Lakes in Washington County
Frequently asked questions about Henry Hagg Lake
Where is Henry Hagg Lake?
- Henry Hagg Lake is a lake in Washington County, Oregon. Its water-quality measurements are published by Oregon DEQ and shown on this page as reported.
What is the water quality of Henry Hagg Lake?
- Henry Hagg Lake in Washington County, Oregon has water-quality measurements published by Oregon DEQ, shown here as reported. Chlorophyll-a (algae): 1.5 µg/L. Surface area: 1157 acres.
Is Henry Hagg Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Are there boat ramps on Henry Hagg Lake?
- Henry Hagg Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Henry Hagg Lake. Public access is listed as yes.
Can I fish at Henry Hagg Lake?
- Henry Hagg Lake 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 Oregon's fish and wildlife agency, so check its current regulations before you go.
Explore Henry Hagg Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Species activity outlook by water temperature and season
Where to stay at Oregon's top lakes, each with its readings
Oregon's cleanest lakes, ranked on agency measurements
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Where this data comes from
7 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Department of Environmental Quality - State of Oregon
OREGONDEQ7 samples · 2024–2025
Analytical methods
- 10200 H ~ Chlorophyll a-b-c Determination
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