El Paso County · Denver Basin (Dawson / Arapahoe)

Well Water in Black Forest / Falcon, Colorado

Black Forest and Falcon sit on the southern edge of the Denver Basin aquifer system, where the Dawson Formation thins dramatically over less than 10 miles. Nearly every home relies on a private well, and the area is ground zero for Colorado's aquifer depletion crisis. Wells that once produced 100 gallons per minute are now lucky to get 40.

Hardness: Moderate to Hard (varies by aquifer depth)

317 fttypical depth drilled (middle half 260–400 ft)

130 fttypical depth to water when drilled

10.4 gal/mintypical pump-test yield

7,167household wells on the state's records here

Typical (median) depth of household wells completed in each period, drawn to scale; the dashed outline reaches the depth that the deeper quarter of wells go past. Blue is where water stood when the wells were finished, where enough records give it. The rock pattern is a sketch of this area's ground, not a log of any one well.

What tested wells showed

Uranium limit 30 µg/L7% of 27 tests over the limit

Arsenic limit 10 µg/L1% of 197 tests over the limit

Nitrate limit 10 mg/L4% of 149 tests over the limit

Bacteria limit any coliform12% of 104 tests over the limit

El Paso County, CDPHE private-well lab results 2011–2020. People usually test because they have a reason to, so these rates describe tested wells, not every well. Bacteria counts any coliform detected.

What to test for and where →

229 permits here are for wells that replaced an earlier well. Wells get replaced when they fail, run dry or are re-drilled deeper, among other reasons.

Every well on record around Black Forest / Falcon

Depth drilledunder 100 ft100–200200–400400–700700 ft +

A random sample of up to 2,500 household wells from the state's permit records, placed by their recorded location and coloured by how deep each was drilled. Locations on permits are often approximate, sometimes only to a section, quarter-section or 40-acre parcel, so a dot marks an area, not a house.

How deep wells have been drilled, decade by decade

Each line hangs from the ground to the median depth of household wells completed that decade; the shaded band is the middle half. Wells drilled later are not the same wells, so a deeper decade can mean falling water, new homes on higher or drier ground, or deeper aquifers being permitted. It is a record of what was drilled, not a single cause.

The Depletion Crisis

The Denver Basin aquifer system beneath Black Forest and Falcon is being pumped far faster than it recharges. Colorado's "100-year rule" — established in 1974 — assumed aquifer water could be withdrawn at 1% per year for a century. We are now 50 years into that 100-year window.

El Paso County adopted a more conservative "300-year rule," but the math is still grim. A deep well into one of the deeper aquifers has a practical lifespan of only 15 to 20 years before it's no longer economical to pump. New deep wells cost over $1 million for water districts. For individual homeowners, replacement wells run $15,000-$50,000+.

A 2024 USGS study found water level declines across all four Denver Basin aquifers in El Paso County, with the Laramie-Fox Hills aquifer declining at 9.9 feet per year — the fastest rate of any layer. The Arapahoe is declining at 1.9 feet per year, the Denver at 3.2 feet per year.

The Thinning Edge

Black Forest sits where the Dawson Formation — the shallowest and most accessible aquifer — thins to its outcrop edge. In less than 10 miles, the Dawson transitions from a thick water-bearing sequence to nothing. This "abrupt reduction in thickness" creates boundary conditions in the aquifer that accelerate depletion.

The population of El Paso County has nearly doubled from 397,890 in 1990 to 731,800 in 2020, and aggressive development continues in the Falcon corridor along Highway 24. Every new subdivision means more straws in a shrinking cup.

Monument, Palmer Lake, Woodmoor, Tri-View, Meridian Ranch, Paint Brush Hills, and Falcon all need more water — and there isn't more water to be had from the Denver Basin.

Upper Black Squirrel Creek — Falcon's Other Aquifer

Parts of the Falcon area also draw from the Upper Black Squirrel Creek alluvial aquifer, a shallow groundwater source. Dry weather and increasing withdrawals have depleted this aquifer severely — approximately 70 of the 100-foot thickness has already been withdrawn, raising serious concern about its future.

Unlike the Denver Basin bedrock aquifers, the Black Squirrel Creek aquifer is alluvial and can recharge, but not at the rate it's being pumped. It's being used up faster than snowmelt can refill it.

What Black Forest / Falcon Well Owners Should Know

If you're on a well in this area, water quantity is as much a concern as water quality. Monitor your well's production rate over time. If yield is declining, you're seeing the aquifer depletion in real time.

For water quality: test for iron, manganese, hardness, bacteria, and nitrates. Deeper wells accessing the Arapahoe or Laramie-Fox Hills aquifers will generally have higher total dissolved solids. The Laramie-Fox Hills can produce water with TDS up to 2,000 mg/L.

Consider water conservation seriously. The Black Forest Water & Wells community organization is a valuable local resource. See our testing guide for labs and costs.

Every well is different. Two wells on the same street can produce completely different water. The data on this page reflects documented conditions in the Black Forest / Falcon area, but the only way to know what's in your water is to test it.

Sources

USGS Scientific Investigations Report 2024-5123 — Groundwater-Level Elevations in Denver Basin Bedrock Aquifers, El Paso County, 2021-24
El Paso County Denver Basin Aquifer Evaluation Report (Moore Engineering, 2024)
Black Forest Water & Wells — Significant Facts About Water and the Denver Basin
USGS Circular 1357 — Water Quality in the Denver Basin Aquifer System