Colorado § 37-90-103 - Definitions - rules.

§ 37-90-103. Definitions - rules.

As used in this article 90, unless the context otherwise requires:

(1) "Alternate point of diversion well" means any well drilled and used, in addition to an original well or other diversion, for the purpose of obtaining the present appropriation of that original well, from more than one point of diversion.

(2) "Aquifer" means a formation, group of formations, or part of a formation containing sufficient saturated permeable material that could yield a sufficient quantity of water that may be extracted and applied to a beneficial use.

(3) "Artesian well" means a well tapping an aquifer in which the static water level in the well rises above where it was first encountered in the aquifer, due to hydrostatic pressure.

(3.5) "Bedrock aquifer" means a designated basin bedrock aquifer.

(4) "Board" or "board of directors" means the board of directors of a ground water management district as organized under section 37-90-124.

(5) "Colorado water conservation board" refers to the board created in section 37-60-102.

(5.5) "Designated basin bedrock aquifer" means a designated groundwater aquifer defined as a bedrock aquifer pursuant to rules adopted by the ground water commission, where water is allocated on the basis of ownership of the overlying land and the available groundwater volume beneath the overlying land.

(6) (a) "Designated groundwater" means that groundwater which in its natural course would not be available to and required for the fulfillment of decreed surface rights, or groundwater in areas not adjacent to a continuously flowing natural stream wherein groundwater withdrawals have constituted the principal water usage for at least fifteen years preceding the date of the first hearing on the proposed designation of the basin, and which in both cases is within the geographic boundaries of a designated groundwater basin. "Designated groundwater" shall not include any groundwater within the Dawson-Arkose, Denver, Arapahoe, or Laramie-Fox Hills formation located outside the boundaries of any designated groundwater basin that was in existence on January 1, 1983.

(b) (I) However, "designated groundwater" may include any groundwater in the Crow Creek drainage area in Weld county, upstream from the confluence of Crow Creek and Little Crow Creek, within the Laramie-Fox Hills formation located outside such boundaries when the Laramie-Fox Hills formation is not overlaid by the Dawson-Arkose, Denver, or Arapahoe formations.

(II) If, upon receipt by the state engineer of the findings of the Laramie-Fox Hills study, as authorized by Senate Bill 250, 1985 legislative session, that the upper Crow Creek drainage area in Weld county, upstream from the confluence of Crow Creek and Little Crow Creek, within the Laramie-Fox Hills formation when the Laramie-Fox Hills formation is not overlaid by the Dawson-Arkose, Denver, or Arapahoe formations should not be a designated groundwater basin, this paragraph (b) is repealed.

(7) "Designated groundwater basin" means that area established by the ground water commission in accordance with section 37-90-106.

(8) "Ground water commission" or "commission" refers to the ground water commission created and provided for in section 37-90-104 to facilitate the functioning of this article.

(9) "Ground water management district" or "district" means any district organized under the provisions of this article.

(10) "Historical water level" means the average elevation of the groundwater level in any area before being lowered by the activities of man, as nearly as can be determined from scientific investigation and available facts.

(10.5) "Nontributary groundwater" means that groundwater, excluding designated groundwater, the withdrawal of which will not, within one hundred years of continuous withdrawal, deplete the flow of a natural stream, including a natural stream as defined in sections 37-82-101 (2) and 37-92-102 (1)(b), at an annual rate greater than one-tenth of one percent of the annual rate of withdrawal. The determination of whether groundwater is nontributary shall be based on aquifer conditions existing at the time of permit application; except that, in recognition of the de minimis amount of water discharging from the Dawson, Denver, Arapahoe, and Laramie-Fox Hills aquifers into surface streams due to artesian pressure, when compared with the great economic importance of the groundwater in those aquifers, and the feasibility and requirement of full augmentation by wells located in the tributary portions of those aquifers, it is specifically found and declared that, in determining whether groundwater of the Dawson, Denver, Arapahoe, and Laramie-Fox Hills aquifers is nontributary, it shall be assumed that the hydrostatic pressure level in each such aquifer has been lowered at least to the top of that aquifer throughout that aquifer; except that not nontributary groundwater, as defined in subsection (10.7) of this section, in the Denver basin shall not become nontributary groundwater as a result of the aquifer's hydrostatic pressure level dropping below the alluvium of an adjacent stream due to Denver basin well pumping activity. Nothing in this subsection (10.5) precludes the designation of any aquifer or basin, or any portion of an aquifer or basin, that is otherwise eligible for designation under the standard set forth in subsection (6) of this section relating to groundwater in areas not adjacent to a continuously flowing natural stream wherein groundwater withdrawals have constituted the principal water usage for at least fifteen years preceding the date of the first hearing on the proposed designation of a basin.

(10.7) "Not nontributary groundwater" means groundwater located within those portions of the Dawson, Denver, Arapahoe, and Laramie-Fox Hills aquifers that are outside the boundaries of any designated groundwater basin in existence on January 1, 1985, the withdrawal of which will, within one hundred years, deplete the flow of a natural stream, including a natural stream as defined in sections 37-82-101 (2) and 37-92-102 (1)(b), at an annual rate of greater than one-tenth of one percent of the annual rate of withdrawal.

(10.9) "Oil and gas well" means a well permitted by the energy and carbon management commission created in section 34-60-104.3 (1) or a well authorized by a federal or tribal entity for the primary purpose of mining, including exploration or production, of petroleum products.

(11) "Person" means any individual, partnership, association, or corporation authorized to do business in the state of Colorado, or any political subdivision or public agency thereof, or any agency of the United States, making a beneficial use, or taking steps, or doing work preliminary to making a beneficial use of designated underground waters of Colorado.

(12) "Private driller" means any individual, corporation, partnership, association, political subdivision, or public agency which operates as lessee or owner its own well drilling rig and equipment and which digs, drills, redrills, cases, recases, deepens, or excavates a well upon the property of such entity.

(12.5) "Quarter-quarter" means a fourth of a fourth of a section of land and is equal to approximately forty acres.

(12.7) "Replacement plan" means a detailed program to increase the supply of water available for beneficial use in a designated groundwater basin or portion thereof for the purpose of preventing material injury to other water rights by the development of new points of diversion, by pooling of water resources, by water exchange projects, by providing substitute supplies of water, by the development of new sources of water, or by any other appropriate means consistent with the rules adopted by the commission. "Replacement plan" does not include the salvage of designated groundwater by the eradication of phreatophytes, nor does it include the use of precipitation water collected from land surfaces that have been made impermeable, thereby increasing the runoff, but not adding to the existing supply of water.

(13) "Replacement well" means a new well which replaces an existing well and which shall be limited to the yield of the original well and shall take the date of priority of the original well, which shall be abandoned upon completion of the new well.

(14) "Resident agriculturist" means a bona fide farmer or rancher residing in the designated groundwater basin whose major source of income is derived from the production and sale of agricultural products.

(15) "State engineer" means the state engineer of Colorado or any person deputized by him in writing to perform a duty or exercise a right granted in this article.

(16) "Subdivision" means an area within a groundwater basin.

(17) "Supplemental well" means any well drilled and used, in addition to an original well or other diversion, for the purpose of obtaining the quantity of the original appropriation of the original well, which quantity can no longer be obtained from the original well.

(18) "Taxpaying elector" means a person qualified to vote at general elections in Colorado, who owns real or personal property within the district and has paid ad valorem taxes thereon in the twenty months immediately preceding a designated time or event, which property is subject to taxation at the time of any election held under the provisions of this article or at any other time in reference to which the term "taxpaying elector" is used. A person who is obligated to pay taxes under a contract to purchase real property in the district shall be considered an owner. The ownership of any property subject to the payment of a specific ownership tax on a motor vehicle or trailer or of any other excise or property tax other than general ad valorem property taxes shall not constitute the ownership of property subject to taxation as provided in this article.

(19) "Underground water" and "groundwater" are used interchangeably in this article and mean any water not visible on the surface of the ground under natural conditions.

(20) "Waste" means causing, suffering, or permitting any well to discharge water unnecessarily above or below the surface of the ground.

(21) (a) "Well" means any structure or device used for the purpose or with the effect of obtaining groundwater for beneficial use from an aquifer. Well includes an augmentation well that diverts groundwater tributary to the South Platte river and delivers it to a surface stream, ditch, canal, reservoir, or recharge facility to replace out-of-priority stream depletions, or to meet South Platte river compact obligations, either directly or by recharge accretions, as part of a plan for augmentation approved by the water judge for water division 1 or a substitute water supply plan approved pursuant to section 37-92-308.

(b) "Well" does not include a naturally flowing spring or springs where the natural spring discharge is captured or concentrated by installation of a near-surface structure or device less than ten feet in depth located at or within fifty feet of the spring or springs' natural discharge point and the water is conveyed directly by gravity flow or into a separate sump or storage, if the owner obtains a water right for such structure or device as a spring pursuant to article 92 of this title.

(22) "Well driller" means any individual, corporation, partnership, association, political subdivision, or public agency which digs, drills, cases, recases, deepens, or excavates a well either by contract or for hire or for any consideration whatsoever.

Source: L. 65: R&RE, p. 1246, § 1. C.R.S. 1963: § 148-18-2. L. 67: p. 275, §§ 1, 2. L. 71: p. 1311, § 1. L. 83: (6) amended, p. 1414, § 1, effective May 23. L. 85: (6) amended, p. 1170, § 1, effective July 1; (10.5) added, p. 1161, § 2, effective July 1. L. 92: (12.5) added and (13) amended, p. 2297, § 1, effective March 19. L. 95: (21) amended, p. 139, § 1, effective April 7. L. 96: (10.5) amended and (10.7) added, p. 1360, § 1, effective June 1. L. 98: (12.7) added, p. 1212, § 2, effective August 5. L. 2003: (21)(a) amended, p. 1453, § 2, effective April 30. L. 2009: (10.5) amended and (10.9) added, (HB 09-1303), ch. 390, p. 2107, § 1, effective June 2. L. 2023: IP and (10.9) amended, (SB 23-285), ch. 235, p. 1257, § 38, effective July 1. L. 2025: (3.5) and (5.5) added, (HB 25-1014), ch. 388, p. 2188, § 8, effective August 6; (10.5) amended, (HB 25-1165), ch. 257, p. 1302, § 9, effective August 6.

Editor's note: (1) The upper Crow Creek drainage area is a designated groundwater basin (see rule 5.2.9 of the ground water commission, 2 CCR 410-1). Therefore, subsection (6)(b) is not repealed.

(2) Section 9(2) of chapter 388 (HB 25-1014), Session Laws of Colorado 2025, provides that the act changing this section applies to well permit applications that are pending before, on, or after August 6, 2025, and to valid well permits in existence before, on, or after August 6, 2025.

Cross references: (1) For the authorization by Senate Bill 85-250 as specified in subsection (6)(b)(II) of this section, see p. 1452 and footnote 70 on p. 1487 of the 1985 general appropriation act, chapter 344, Session Laws of Colorado 1985.

(2) For the legislative declaration in HB 25-1165, see section 1 of chapter 257, Session Laws of Colorado 2025.

ANNOTATION

Law reviews. For note, "Appropriation and Colorado's Ground Water: A Continuing Dilemma?", see 40 U. Colo. L. Rev. 133 (1967). For article, "Recent Developments in Colorado Groundwater Law", see 58 Den. L.J. 801 (1981). For article, "Water Rights — How to Avoid Getting in Over Your Head", see 11 Colo. Law. 2143 (1982). For article, "Water for Mining and Milling Operations — Part I", see 13 Colo. Law. 240 (1984). For article, "Principles and Law of Colorado's Nontributary Ground Water", see 62 Den. U. L. Rev. 809 (1985). For article, "The Continuing Groundwater Saga — Part I: Senate Bill 5", see 15 Colo. Law. 422 (1986).

Commission to categorize ground water as "underground water" or "designated ground water". The general assembly left categorization of ground water as "underground water" or as "designated ground water" as a factual matter to be resolved by the ground water commission when it established designated ground water basins. Pioneer Irrigation Dists. v. Danielson, 658 P.2d 842 (Colo. 1983).

Tributary character of water held to meet definition of "designated ground water". Kuiper v. Lundvall, 187 Colo. 40, 529 P.2d 1328 (1974).

Plaintiff's application for surface water rights properly denied because the streams at issue met the definition of "designated groundwater". The streams were man-made by the plaintiff, resulted from storm runoff increased by plaintiff's construction of impermeable surfaces, and amounted to a concrete catch pond. Therefore, the water in the streams was not water that, under natural conditions and in its natural course, would be available for the fulfillment of decreed surface rights. In Matter of Water Rights, 2015 CO 64, 361 P.3d 392.

Applications for appropriating designated ground water committed to commission's jurisdiction. Applications for the appropriation of designated ground water to a beneficial use are committed to the jurisdiction of the ground water commission. State ex rel. Danielson v. Vickroy, 627 P.2d 752 (Colo. 1981); In Matter of Water Rights, 2015 CO 64, 361 P.3d 392.

Vickroy decision not retrospectively applied. State ex rel. Danielson v. Vickroy (627 P.2d 752 (Colo. 1981)) should not be retrospectively applied to those decrees involving well permits in designated ground water basins issued prior to the Vickroy decision. Ground Water Comm'n v. Shanks, 658 P.2d 847 (Colo. 1983).

Under the definition of nontributary groundwater under subsection (10.5), whether groundwater is nontributary is not dependent upon the quantitative effect that a well has on a stream but rather upon the annual withdrawal rate and a measure of the relationship between that rate and the resulting stream depletions. State Eng'r v. Castle Meadows, Inc., 856 P.2d 496 (Colo. 1993).

Subsection (10.5) is not a useful tool for evaluating the significance of the effect that stream depletions will have on vested rights and does not determine the injurious nature of a withdrawal. State Eng'r v. Castle Meadows, Inc., 856 P.2d 496 (Colo. 1993).

The 1996 amendments to the definition of nontributary groundwater were specifically tailored to address issues raised in previous court cases, thus demonstrating clear legislative intent that the amended definition should apply to pending decrees and permit applications. Chatfield E. Well Co. v. Chatfield E. Prop. Owners Ass'n, 956 P.2d 1260 (Colo. 1998).

Unconfined aquifer found to be part of a natural surface stream within the meaning of subsection (10.5). Am. Water Development, Inc. v. City of Alamosa, 874 P.2d 352 (Colo. 1994).

Amount of surface stream depletion alone does not determine whether water is nontributary under the meaning of subsection (10.5). The underflow and tributary waters of streams described in the natural stream legislation are included as part of the natural streams and the effect on such underflow and tributary waters must be considered in determining whether ground water to be withdrawn is nontributary. Am. Water Dev., Inc. v. City of Alamosa, 874 P.2d 352 (Colo. 1994).

Not nontributary ground water is limited to aquifers in the Denver basin, and the Laramie-Fox aquifer located in Park county therefore cannot be not nontributary ground water. Water Rights of Park County Sportsmen's Ranch LLP v. Bargas, 986 P.2d 262 (Colo. 1999).

Gravel pits which will be reclaimed by being filled with ground water obtained from an aquifer are "wells" under the statutory definition of the term. Three Bells Ranch v. Cache La Poudre, 758 P.2d 164 (Colo. 1988); Zigan Sand & Gravel v. Cache Le Poudre, 758 P.2d 175 (Colo. 1988).

A permit is required for the extraction of methane from coal beds because such an oil and gas well has the effect of obtaining ground water for beneficial use, and is therefore a "well" as defined in this article notwithstanding the Colorado oil and gas commission's exclusive jurisdiction over oil and gas operations. Vance v. Wolfe, 205 P.3d 1165 (Colo. 2009).

Replaced wells must be abandoned. The statutory definition of "replacement well" imposes the obligation to abandon replaced wells upon completion of replacement wells. Broyles v. Ft. Lyon Canal Co., 638 P.2d 244 (Colo. 1981).

Because no prior supreme court decision mandates that a well owner's replaced wells be plugged according to administrative regulations, the water court must exercise its own discretion, as limited by statutes, supreme court decisions, and particular facts of the case, to determine whether to require the well owner to plug his replaced wells. Broyles v. Ft. Lyon Canal Co., 695 P.2d 1136 (Colo. 1985).

Judgment upheld designating area as ground water basin. Hayes v. State, 178 Colo. 447, 498 P.2d 1119 (1972).

Applied in Colo. Ground Water Comm'n v. Dreiling, 198 Colo. 560, 606 P.2d 836 (1979).