Colorado · counties
Water in Boulder County
What the state and federal record says about water across Boulder County. Each figure names the agency it came from.
Can I drill a well here?
It depends on your lot: its size, and when it was created
-
Where the lot decides (over-appropriated ground)
What a household well may serve depends on the lot's size and on when and how it was created:
Lot of 35 acres or more
A household well can serve up to three homes, one acre of lawn and garden, and livestock. A 35-acre tract platted as part of a subdivision counts as part of the subdivision instead.
Under 35 acres, created before June 1, 1972 or by a county exemption
A household well for use inside one house only. No lawn, garden or livestock.
Under 35 acres, in a subdivision approved June 1, 1972 or later
No well by right. DWR weighs every well in the subdivision together, so in practice the subdivision's own water supply plan decides what a well may do.
- One exempt well per legal parcel. Inside a town or a water district's service area DWR generally issues no household well permit.
What has actually been permitted in Boulder County
- 752household well permits issued since 2015
- 350of them for use inside the house only
- 402for full household use
- 220feet, the typical depth
- 8gallons a minute, the typical yield
CDSS well permits Decided by: DWR, at permit application. Appeals go to the water judge within 35 days.
- 4,147 Live water rights across 743 square miles
- 13,773 Wells drilled across 743 square miles
- 39,572 ac Irrigated ground across 743 square miles
- 173 ft Well depth middle value across 533 of 743 square miles
- 207 days Days called out middle value across 470 of 743 square miles
Point at any square mile to read what is on it. Hover the maps below to compare them.
Boulder County by the square mile
Each figure below is one number for the whole county. The map places the same records on the ground, square mile by square mile.
Live water rights. Decreed rights still on the books. This is where the paper water is, which is not the same map as where anybody drilled.
- none on record (bare ground)
- up to 1
- 2
- 3
- 4 to 6
- 7 to 16
- over 16
743 surveyed sections, drawn one square mile to a square. The shading is scaled against every county in Colorado, so a color means the same thing on any of these pages. The outline is the county boundary from the Census Bureau: ground inside the line and outside the shading is ground nobody has drilled, filed on or addressed. Aerial imagery is the USGS National Map.
There are dams here that would take lives if they failed
36 of this county's 115 dams are rated high hazard. Hazard is about what is DOWNSTREAM rather than about the dam's condition, so a high-hazard rating means people or roads below it, and it is what drives the inspection and the owner's liability.
Colorado Dam Safety 2 of 56 counties
36 here 2nd of 56 One bar per Colorado county from lowest to highest. Point at one to name it.
Wells here have had to be re-drilled deeper
97 wells carry a later record more than 20% deeper than their first. Colorado publishes no water-level trend, so a well going back down is the closest thing to one.
CDSS well permit action history 4 of 61 counties
97 here 4th of 61 One bar per Colorado county from lowest to highest. Point at one to name it.
Towns hold a large share of the water here
38% of rights allow municipal use. Municipal rights are senior more often than not and rarely come back on the market, so they shape what is left for everyone else.
CDSS water rights, net amounts 7 of 58 counties
38% here 7th of 58 One bar per Colorado county from lowest to highest. Point at one to name it.
Wells here make very little water
The typical well makes 7 gallons a minute, against 12 gpm in the median county. Workable for a house, a problem for livestock or irrigation.
CDSS well permits 7 of 64 counties
7 gpm here 7th of 64 One bar per Colorado county from lowest to highest. Point at one to name it.
A lot of this county is wet ground
75% of sections carry poorly drained soil, meaning a water table close to the surface for part of the year. A foundation and septic constraint, and often the most productive ground on a property.
USDA SSURGO soil survey 9 of 63 counties
75% here 9th of 63 One bar per Colorado county from lowest to highest. Point at one to name it.
Water systems here have unresolved health violations
4 of this county's 41 community water systems carry a health-based violation that has not been returned to compliance. Health-based means contamination or a treatment failure, not late paperwork.
EPA Safe Drinking Water Information System 11 of 45 counties
4 here 11th of 45 One bar per Colorado county from lowest to highest. Point at one to name it.
Dams here are rated unsatisfactory
4 of this county's 115 dams carry an unsatisfactory condition rating. A storage right behind a failing dam is water you cannot count on.
Colorado Dam Safety 12 of 43 counties
4 here 12th of 43 One bar per Colorado county from lowest to highest. Point at one to name it.
The senior water here was claimed before Colorado was a state
The oldest appropriation on record in this county is 1859, which predates statehood in 1876. Seniority is the whole of Colorado water law and it is absolute: a right from the 1850s is in front of everything filed since, every year, in every dry year.
CDSS water rights, net amounts 4 of 60 counties
1859 here 4th of 60 One bar per Colorado county from lowest to highest. Point at one to name it.
Wells here get plugged and abandoned more than most
12.8% of well permits end in a plugging, 1,470 wells in all. A well sealed shut is the clearest verdict a driller ever files.
CDSS well permit action history 21 of 64 counties
12.8% here 21st of 64 One bar per Colorado county from lowest to highest. Point at one to name it.
Water here is called out for a large part of the year
The median right is out of priority 175 days a year on DWR's own analysis. The worst year on record here was 366 days.
DWR administrative call analysis 25 of 48 counties
175 days here 25th of 48 One bar per Colorado county from lowest to highest. Point at one to name it.
Most of the wells drilled here never had a pump put in
60% of constructed wells have no pump installation on record. Somebody paid to drill a hole and walked away from it. A permit says you may drill; this is what happened when people did.
CDSS well permit action history 28 of 64 counties
60% here 28th of 64 One bar per Colorado county from lowest to highest. Point at one to name it.
Ground here is prime farmland, but only if it is irrigated
42% of sections carry soil the USDA classes as 'prime farmland if irrigated'. That qualifier is the whole sentence: the soil is excellent and the classification depends on water reaching it. It is what an appraiser and a conservation easement both test against.
USDA SSURGO soil survey 33 of 56 counties
42% here 33rd of 56 One bar per Colorado county from lowest to highest. Point at one to name it.
For one parcel in Boulder County
The figures above describe the whole county. The Land, Development and Rights reports answer for one parcel: what water conveys, what a well permit would allow, and what the county requires to split it. Each answer gives the evidence within a mile and who decides.
Search an address in Boulder County