| Colorado Water Law | Ground Water |
| Surface Water | Ground Water Well Permitting |
Colorado Water Law
Colorado water law follows the system of prior appropriation. The prior appropriation “doctrine” is a system of allocating water rights from a water body or source (surface water or ground water) that has evolved in the American West since the mid 1800’s due to the scarcity of water.
Surface Water
Surface water rights are regulated in Douglas County under the Doctrine of Prior Appropriation. The doctrine prior appropriation can be summarized in the following phrase: “first in time/first in right.” This means that the first person to “beneficially” use water from a water body becomes the senior water rights holder (the water is appropriated), and has the right to continue to use that quantity of water for that purpose. The remaining water on that water body can be used by subsequent users, the junior water rights holders, for their own beneficial purposes provided that they do not harm the rights of senior water users. Each water right has an appropriation date and a yearly quantity of water that may be used. In times of drought, senior water right holders can use all of their appropriated water provided the water source can supply it. This is irregardless of whether or not there is enough water left for junior water holders; however, depending on the available water, junior water holders may receive a portion of their full allocation.
Acquiring a valid water right necessitates establishing intent to divert water, which is the act of diverting the water and applying that water to a beneficial use. In addition, surface water rights are not connected to land ownership and can, with certain restrictions, be sold and acquired as surface property.
The term beneficial use is very important because it historically establishes the foundation, measure, and limit of the water for that water right holder. The definition of beneficial use is commonly delineated for household, agricultural and industrial purposes. According to Colorado water law, beneficial use is broadly defined as a lawful appropriation that employs reasonably efficient practices to put that water to use without waste. In order to have enough water available to as many water rightholders as possible, avoiding water waste is the goal. The uses that are considered beneficial have evolved and increased in response to Colorado’s changing community and economic values. For example, an environmental and ecological purpose, such as maintaining the wildlife habitat that is dependent on a natural body of water, is now considered to be a beneficial use under Colorado water law.
Ground Water
Ground water in Colorado is administered and managed under four categories: (1) Tributary ground water; (2) Designated ground water; (3) Non-tributary ground water; and (4) Denver Basin ground water. Designated ground water, non-tributary ground water and Denver Basin ground water are not subject to the doctrine of prior appropriation discussed in detail under the surface water section.
Tributary Ground Water
Tributary ground water is water in an aquifer that is hydraulically connected to surface water, meaning if you pull water out of the ground you have an impact to the surface water flows of the stream. Examples of tributary ground water in Douglas County are the alluvial aquifers that underlie the South Platte River, and Cherry Creek. In contrast, deep ground water in not measurably connected to surface water due to the confining layers that overly the aquifer.
The State Engineer’s Office issues or denies well permits for appropriation of tributary ground water.
Designated Ground Water
Designated ground water is defined as water that is not used to supplement or recharge continuously flowing surface streams under natural conditions, i.e., it is not hydraulically connected to the surface water system. On the Colorado Eastern Plains, there are eight designated basins: Northern High Plans, Upper Big Sandy, Southern High Plains, Upper Black Squirrel Creek, Kiowa Bijou, Camp Creek, Lost Creek, and Upper Crow Creek. A modified system of prior appropriation governs designated ground water.
Designated ground water is managed by the Colorado Ground Water Commission. There are no designated ground water basins within Douglas County.
Non-Tributary Ground Water
Non-tributary ground water is water that is physically separated from surface water by impermeable layers in the aquifer. It is also considered non-tributary when the ground water is at such a great distance from the surface water that it has little or no hydraulic connection with it. In a non-tributary aquifer, the landowner overlying the aquifer has the ability to pump the ground water as long as it will not affect surface water levels at an annual rate greater than one-tenth of one percent of the annual rate of withdrawal within 100 years. Under this system of water management, obtaining and exercising non-tributary ground water rights emulates the basic concepts of beneficial use, non-waste and anti-speculation.
Denver Basin Ground Water
Denver Basin ground water is presumed not to be tributary in nature. Water from the Denver Basin refers to deep ground water withdrawn from one of its four aquifers; Dawson, Denver, Arapahoe, and Laramie-Fox Hills.
The Denver Basin contains two types of legally designated ground water, non-tributary and not non-tributary. Denver Basin ground water is allocated to overlying landowners, and rights to withdraw water are subject to augmentation requirements under the two separate legal designations.
Non-tributary ground water was previously described in the previous section.
Not non-tributary ground water is legally defined as ground water located within those portions of the Denver Basin aquifers that are outside the boundaries of any designated basin and will, within 100 years, deplete the flow of a natural stream at an annual rate greater than one-tenth of one percent of the annual rate of withdrawal. Pumping not-non-tributary ground water requires an augmentation plan from the State Engineers Office and varies in the amount of required return flow based on the proposed aquifer and the location of the well with respect to the stream/aquifer connection.
Denver Basin Rules
The Denver Basin Rules (the rules) apply to the Dawson, Denver, Arapahoe and Laramie-Fox Hills aquifers in the Denver Basin, and provide estimated saturated thickness and specific yields of each aquifer. The State Engineer uses the rules to evaluate and determine the amount of ground water available for withdrawal where no specific site data is available. Upon evaluation under these criteria, a well permit may or may not be issued. The applicant can augment the values with site specific well log data, which demonstrates that the actual aquifer characteristics are different from the general information given in the rules.
For more information about water law in Colorado, please refer to the Colorado Division of Water Resources, the Office of the State Engineer.
Ground Water Well Permitting
There are two statutes that govern the permitting of wells, CRS 37-90-137 and 37-92-602. Well permitting under Section 137 is for “non-exempt” wells and permitting under Section 602 is for “exempt” wells.
Non-Exempt Wells
Non-exempts wells include municipal, irrigation, commercial and industrial wells, but it also includes residential wells on tracts of 35 acres, or larger, if the volume to be diverted by the well is greater than 1 acre-feet/year, and residential wells on tracts of less than 35 acres if the use is going to be greater than household use only.
The 600 foot spacing rule is in Section 137 (37-90-137(2)(b)(I)), applies to all non-exempt wells, but does not apply to exempt wells, except in special circumstances. If a well is permitted under Section 602, there is not a well spacing requirement that has to be met. This would include domestic well permits obtained for rural site plans and permits under cluster 35 development requirements, as the density of the wells is still 1 per 35 acres, which qualifies as exempt (CRS 137-90-602(3)(b)(II)(A)). Spacing requirements would also not apply to any household use only, or commercial exempt wells.
The 600-feet spacing rule does apply to all municipal, commercial, irrigation and industrial wells, and it also may apply to any residential well that obtains its water supply subject to an adjudicated decree and is permitted to pump greater than 15 gpm. If a residential well adjudicated under Section 137, is located less than 600-feet from other exiting wells, but is permitted for 15 gpm or less, there is no well spacing requirement (CRS 37-90-137(2)(b)(III)).
Exempt Wells
Exempt wells include (a) household use only wells (limited to a maximum pumping rate of 15 gallons per minute (gpm), up to a maximum annual volume of 0.33 acre-feet/year, and with no outside uses allowed), (b) commercial exempt wells (limited to a maximum pumping rate of 15 gpm, up to a maximum annual volume of 0.33 acre feet/year, and no outside uses allowed), and (c) domestic wells which by definition, means a single well on a 35 or larger-acre tract that will be the only well on that tract and will not exceed a pumping rate of 15 gpm and an annual use of 1 acre-foot. The reason that the exempt wells in (a) and (b) say “up to a maximum of 0.33 acre feet/year” is because that is the maximum allowed by statute, but if there is less than 0.33 acre feet per year legally available beneath the property, the permit could allow less water usage. If, by virtue of the location of the property, use of the proposed water supply needs an augmentation plan, the well has to be permitted as a non-exempt well regardless of parcel size or the volume of water that is desired to be extracted.
In summary, there is not a well spacing requirement for any individual residential well, as long as the permitted pumping rate is equal to, or less than, 15 gpm, regardless of whether it is permitted as an exempt domestic well, an exempt well in a cluster 35 development, or as a non-exempt residential well on a parcel of any size.