Patagonia Lake
Santa Cruz County, Arizona260 acresView mapDirections
No nutrient or algae sampling on record from ADEQ for this lake.
- Impaired · Mercury
- 16 ft max depth
- Public access
- Limited data
Patagonia Lake in Santa Cruz County, Arizona has water-quality measurements published by ADEQ, shown here as reported. Surface area: 260 acres.
Patagonia Lake is a 260-acre lake in Santa Cruz County, Arizona with an estimated average depth of about 16 feet. Water clarity is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, ADEQ, last sampled 2026-04-06. Methodology: how these readings are compared.
Patagonia Lake covers about 260 acres in Santa Cruz County. It has one public boat landing. For a place on the water, look through cabin and lake-house rentals near Patagonia Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Patagonia Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Patagonia Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Patagonia Lake is safe to swim in today is a call for the Arizona Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Patagonia Lake
These are the measurements ADEQ publishes for Patagonia 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 Patagonia Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~16 ft est.
Surface area
260 acres
Public access
Yes
Listed by ADEQ
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Arizona has not published bathymetry for Patagonia Lake.
Lake Size & Watershed
Watershed (drainage) area
238 sq mi
HydroLAKES / HydroSHEDS
Shoreline
3.4 mi
HydroLAKES / HydroSHEDS
Elevation
3,776 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Patagonia 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 Patagonia Lake
Compare lakeside cabins, hotels, and vacation rentals near Patagonia Lake in Santa Cruz County, Arizona — 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 Patagonia Lake
Prices for Oct 30–Nov 1, 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 trip? Cabins and lodging at Patagonia Lake → · more Arizona lake trips
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Fishing Patagonia Lake
Water quality readings over time
3 seasons of samples on record (2014–2019). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Phosphorus
Worsening+12.25 µg/L/yr2 years
Reservoir Info (USACE NID)
Patagonia Lake is a man-made reservoir impounded by the Lake Patagonia (completed 1968), built primarily for recreation on the Sonoita Creek; earth-type dam, 157 ft tall and 970 ft long.
- Surface area
- 260 ac
- Normal storage
- 7,540 ac-ft
- Drainage area
- 235 sq mi
- Hazard class
- High
- Owner
- ARIZONA STATE PARKS
Source: USACE National Inventory of Dams, NID ID AZ00029 · Operator website
EPA Impairment Status
Patagonia Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Fish consumption.
Source: EPA ATTAINS assessment unit AZL15050301-1050_00 · Official waterbody report
Nearby Lakes in Santa Cruz County
Frequently asked questions about Patagonia Lake
Where is Patagonia Lake?
- Patagonia Lake is a lake in Santa Cruz County, Arizona. Its water-quality measurements are published by ADEQ and shown on this page as reported.
What is the water quality of Patagonia Lake?
- Patagonia Lake in Santa Cruz County, Arizona has water-quality measurements published by ADEQ, shown here as reported. Surface area: 260 acres.
Is Patagonia Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Patagonia Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
How deep is Patagonia Lake?
- No published bathymetric survey covers Patagonia Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 16 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 260 acres.
Are there boat ramps on Patagonia Lake?
- Patagonia Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Patagonia Lake. Public access is listed as yes.
Can I fish at Patagonia Lake?
- Patagonia 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 Arizona's fish and wildlife agency, so check its current regulations before you go.
Explore Patagonia Lake across LakeQuality
2 thermal springs within 15.2 mi, nearest Monkey Spring
Species activity outlook by water temperature and season
Where to stay at Arizona's top lakes, each with its readings
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Where this data comes from
5 measurements from 1 monitoring station, 2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Great Lakes Environmental Center
GLEC5 samples · 2026
Analytical methods
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 300.0 ~ EPA; Determination of Inorganic Anions by Ion Chromatography
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory