Colorado Division of Water Resources
1313 Sherman Street, Suite 821
Denver, Colorado 80203
www.water.state.co.us
303-866-3581
September 2013
Guide to Well Permit Numbering
The State of Colorado began issuing well permits in 1953 and from that time until 1957, well permits
were issued by the Colorado Water Conservation Board. In 1957, the responsibility for issuing well
permits was transferred to the Colorado Division of Water Resources (State Engineer). Over the
years, the well permit numbering system has evolved. The information in this document should be
used as a guide to understand the typical meaning of permit number suffixes. Generally, a permit
without a suffix is an exempt or small capacity well and a permit with a suffix is a non-exempt or
large capacity well. There will always be exceptions to the information in this document. Use this
document as a guide only, and consult the permit file for details on a specific permit.
The well permit number is a combination of three fields on the well database:
1) The permit number
2) The permit number suffix
3) The permit number replacement code
1) The permit number is a one to six digit number that may or may not include a replacement code
and/or suffix. (The suffix “AB” may contain seven digits.)
2) The permit number suffix may include up to three letters. Typically used suffixes:
Permit Number Suffix
F
Description
Non-exempt permit (issued pursuant to §37-90-137, C.R.S.) or large capacity permit
(issued pursuant to §37-90-107).
AD
Denied well permit application. Well permit not issued.
MH
“Notice” provided pursuant to Rule 6.3 of Water Well Construction Rules for
construction of temporary monitoring and observation hole or temporary test hole.
DW
“Notice” provided pursuant to Rule 6.3 of Water Well Construction Rules for
construction of temporary dewatering well.
G
GX
Geothermal well permit issued pursuant to § 37-90.5-107, C.R.S.
Geoexchange system permit issued pursuant to § 37-90.5-106, C.R.S. This is an
annual license issued to contractors to allow the contractor to construct multiple
geoexchange (closed-loop) systems statewide. When “As-built” construction
details for individual systems are submitted to DWR, they are also entered on the
well database under the same license number, thus many entries may exist under
one number with the “GX” suffix.
M
R, S, T, U, V, etc.
RDS, RDT, etc.
MFP
R, RD
RN, N, RNA
TH, TW
Permits for monitoring wells were issued as non-exempt or large capacity from
November 1984 until March 1992. Monitoring well permits have been issued as
exempt or small capacity wells since March 1992.
Recording/Registration of map filings of non-exempt or large capacity wells from
the 1950’s and early 1960’s. If multiple wells were registered from one map filing,
the first well was assigned suffix “R”, the second well was assigned suffix “S”, the
third well was assigned suffix “T”, etc. If the wells were also known to be decreed
by the water court, the suffix “RDS, RDT, etc., may have been used. A few
registrations of map filings have also used the suffix “MFP”.
Registration of a non-exempt well from the 1950’s and early 1960’s. If the well was
also known to be decreed by water court, the suffix “RD” may have been used.
Registration of an exempt or small capacity well from the 1950’s and early 1960’s.
At that time, “RN” indicated “Registered, no fee required”. NOTE- In some cases,
the suffix “N” and “RNA” may have also been used for exempt or small capacity
wells.
Test hole or test well – temporary structure. “MH” code used after 1988.
VE
Indicates verbal approval granted for emergency replacement of an existing well.
An application for a replacement (redrill) permit was required to be submitted by
the well owner within 10 days following issuance of the verbal approval. Approval
of verbals discontinued June 1, 2000.
FP, RFP
Final permit for large capacity well in designated ground water basin. RFP indicates
a final permit issued for a well that was previously registered with the suffix “R”.
BD
Used to identify a Denver Basin water right within the boundaries of the Designated
Ground Water Basins. This is not a water well permit.
WCB
AB
Well permit originally issued by Colorado Water Conservation Board. Numbering
system began with permit no. 1 in each county, thus must review county and well
location to distinguish between duplicate permit numbers on well database.
Indicates a well abandonment report has been submitted for an un-permitted well.
3) The permit number replacement code is limited to either the letters A or R. This field is left blank
unless the permit was issued for a replacement well.
“A” is used to indicate a replacement permit (redrill) for exempt wells or small capacity wells.
“R” is used to indicate a replacement permit (redrill) for non-exempt wells or large capacity
wells.
Colorado Division of Water Resources:
Permit Numbering System Guide
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