CO Code § 31-23-301 (2021)
2021 Colorado Code|Title 31 - Government - Municipal|Article 23 - Planning and Zoning|Part 3 - Zoning|§ 31-23-301. Grant of Power

  Except as otherwise provided in section 34-1-305, C.R.S., for the purpose of promoting health, safety, morals, or the general welfare of the community, including energy conservation and the promotion of solar energy utilization, the governing body of each municipality is empowered to regulate and restrict the height, number of stories, and size of buildings and other structures, the percentage of lot that may be occupied, the size of yards, courts, and other open spaces, the density of population, the height and location of trees and other vegetation, and the location and use of buildings, structures, and land for trade, industry, residence, or other purposes. Regulations and restrictions of the height, number of stories, and the height and location of trees and other vegetation shall not apply to existing buildings, structures, trees, or vegetation except for new growth on such vegetation. Such regulations shall provide that a board of adjustment may determine and vary their application in harmony with their general purpose and intent and in accordance with general or specific rules contained in such regulations. Subject to the provisions of subsection (2) of this section and to the end that adequate safety may be secured, said governing body also has power to establish, regulate, restrict, and limit such uses on or along any storm or floodwater runoff channel or basin, as such storm or floodwater runoff channel or basin has been designated and approved by the Colorado water conservation board, in order to lessen or avoid the hazards to persons and damage to property resulting from the accumulation of storm or floodwaters. Any ordinance enacted under authority of this part 3 shall exempt from the operation thereof any building or structure as to which satisfactory proof is presented to the board of adjustment that the present or proposed situation of such building or structure is reasonably necessary for the convenience or welfare of the public.    The power conferred by subsection (1) of this section for flood prevention and control shall not be exercised to deprive the owner of any existing property of its future use or maintenance for the purpose to which it was lawfully devoted on February 25, 1966, but provisions may be made for the gradual elimination of uses, buildings, and structures, including provisions for the elimination of such uses when the existing uses to which they are devoted are discontinued, and for the elimination of such buildings and structures when they are destroyed or damaged in major part.    The governing body of any municipality or the board of adjustment thereof, in the exercise of powers pursuant to this section, may condition any zoning regulation, any amendment to such regulation, or any variance of the application thereof or the exemption of any building or structure therefrom upon the preservation, improvement, or construction of any storm or floodwater runoff channel designated and approved by the Colorado water conservation board.    A statutory or home rule city or town or city and county shall not enact an ordinance prohibiting the use of a state-licensed group home for either persons with intellectual and developmental disabilities or behavioral or mental health disorders that serves not more than eight persons with intellectual and developmental disabilities or eight persons with behavioral or mental health disorders and appropriate staff as a residential use of property for zoning purposes. As used in this subsection (4), the phrase “residential use of property for zoning purposes” includes all forms of residential zoning and specifically, although not exclusively, single-family residential zoning.      As used in this subsection (5), unless the context otherwise requires:   Repealed.    “Equivalent performance engineering basis” means that by using engineering calculations or testing, following commonly accepted engineering practices, all components and subsystems will perform to meet health, safety, and functional requirements to the same extent as required for other single family housing units.         No municipality may have or enact zoning regulations, subdivision regulations, or any other regulation affecting development that exclude or have the effect of excluding homes from the municipality that are: (b) (I) No municipality may have or enact zoning regulations, subdivision regulations, or any other regulation affecting development that exclude or have the effect of excluding homes from the municipality that are:   Homes certified by the division of housing created in section 24-32-703 or a party authorized to act on its behalf;    Homes certified by the United States department of housing and urban development through its office of manufactured housing programs, a successor agency, or a party authorized to act on its behalf; or    Homes that meet or exceed, on an equivalent performance engineering basis, standards established by the municipal building code.       Nothing in this subsection (5) shall prevent a municipality from enacting any zoning, developmental, use, aesthetic, or historical standard, including, but not limited to, requirements relating to permanent foundations, minimum floor space, unit size or sectional requirements, and improvement location, side yard, and setback standards to the extent that such standards or requirements are applicable to existing or new housing within the specific use district of the municipality.    Nothing in this subsection (5) shall preclude any municipality from enacting municipal building code provisions for unique public safety requirements such as snow load roof, wind shear, and energy conservation factors, unless the home is certified by the division of housing created in section 24-32-704 or a party authorized to act on its behalf or the United States department of housing and urban development through its office of manufactured housing programs, a successor agency, or a party authorized to act on its behalf. A municipality must comply with section 24-32-3318 when enacting building code provisions for a manufactured home as defined in section 24-32-3302 (20).    Nothing in this subsection (5) shall be deemed to supersede any valid covenants running with the land.           History. Source: L. 75: Entire title R&RE, p. 1155, § 1, effective July 1; (4) added, p. 934, § 57, effective July 1. L. 79: (1) amended, p. 1163, § 13, effective January 1, 1980. L. 84: (5) added, p. 824, § 2, effective January 1, 1985. L. 87: (4) amended, p. 1217, § 2, effective July 1. L. 2006: (4) amended, p. 1408, § 76, effective August 7. L. 2017: (4) amended,(SB 17-242), ch. 263, p. 1379, § 300, effective May 25. L. 2021: (5)(a)(I) repealed and (5)(b)(I) and (5)(b)(III) amended,(HB 21-1019), ch. 122, p. 486, § 30, effective September 7.    Editor's note:   This section is similar to former § 31-23-201 as it existed prior to 1975.   Cross references:   For the legislative declaration in SB 17-242, see section 1 of chapter 263, Session Laws of Colorado 2017.   ANNOTATION   Law reviews. For article, “Colorado Needs a Constitutional and Effective Roadside Sign Law”, see 36 Dicta 475 (1959). For note, “Spot Zoning”, see 34 Rocky Mt. L. Rev. 231 (1962). For note, “Zoning Variances -- The Colorado Position”, see 34 Rocky Mt. L. Rev. 382 (1962). For article, “1974 Land Use Legislation in Colorado”, see 51 Den. L.J. 467 (1974). For comment, “Regionalism or Parochialism: The Land Use Planner's Dilemma”, see 48 U. Colo. L. Rev. 575 (1977). For article, “Cumulative Impact Assessment of Western Energy Development: Will it Happen?”, see 51 U. Colo. L. Rev. 551 (1980). For article, “Winning the Rezoning”, see 11 Colo. Law. 634 (1982). For article, “The Emerging Relationship Between Environmental Regulations and Colorado Water Law”, see 53 U. Colo. L. Rev. 597 (1982). For note, “Referendum and Rezoning”, see 53 U. Colo. L. Rev. 745 (1982). For note, “The Permissible Scope of Compulsory Requirements for Land Development in Colorado”, see 54 U. Colo. L. Rev. 447 (1983). For article, “The Antitrust Challenge to Local Government Protection of the Central Business District”, see 55 U. Colo. L. Rev. 21 (1983). For article, “Judicial Review, Referral and Initiation of Zoning Decisions”, see 13 Colo. Law. 387 (1984). For comment, “State and Local Regulation of Timesharing in Colorado”, see 56 U. Colo. L. Rev. 289 (1985). For article, “Transferable Development Rights and Their Application in Colorado: An Overview”, see 34 Colo. Law. 75 (March 2005). For article, “Group Home Regulations Under State and Federal Law”, see 35 Colo. Law. 37 (Feb. 2006).   Annotator's note. Since § 31-23-301 is similar to former § 31-23-201 prior to the 1975 repeal and reenactment of this title, and laws antecedent thereto, relevant cases construing those provisions have been included in the annotations to this section.   General assembly has power to legislate zoning regulations applicable to statutory cities, as distinguished from home rule cities. Glennon Heights, Inc. v. Central Bank & Trust, 658 P.2d 872 (Colo. 1983).   Subsection (4) constitutes a legitimate limitation on the legislative powers delegated to statutory cities. Glennon Heights, Inc. v. Central Bank & Trust, 658 P.2d 872 (Colo. 1983).   State has authority to enact legislation for the welfare of developmentally disabled citizens under its police powers. Glennon Heights, Inc. v. Central Bank & Trust, 658 P.2d 872 (Colo. 1983).   Exemption of municipal activities from zoning ordinances. Exemption from zoning ordinance must be pursuant to statutory procedure, and the governmental/proprietary distinction is rejected as a means for determining when a municipality must obey its zoning ordinances. Clark v. Town of Estes Park, 686 P.2d 777 (Colo. 1984).   Zoning is a matter of local and municipal concern. Serv. Oil Co. v. Rhodus, 179 Colo. 335 , 500 P.2d 807 (1972); Nopro Co. v. Town of Cherry Hills Vill., 180 Colo. 217 , 504 P.2d 344 (1972); City of Greeley v. Ells, 186 Colo. 352 , 527 P.2d 538 (1974).   Zoning laws is an area which is best left to local government, and decisions which relate to the decided course of community development should be upheld, even though a reviewing court may disagree with the wiseness of the municipality's choice. Rademan v. City & County of Denver, 186 Colo. 250 , 526 P.2d 1325 (1974).   City council did not abuse its discretion or exceed its jurisdiction in denying application to rezone property from residential to limited residential-commercial when there was competent evidence of a factual basis in support of the zoning decision. Christiansen v. Golden City Council, 757 P.2d 1121 (Colo. App. 1988).   Section does not make counties immune or exempt from municipal zoning requirements. La Plata County Comm'rs v. Bd. of Adjustment, 768 P.2d 1250 (Colo. App. 1988).   Board of county commissioners did not exceed its jurisdiction or abuse its discretion when it concluded that a pre-parole facility proposed use conformed to the PUD zone district since it was representative of the class “hospitals, nursing homes, and mental or physical rehabilitation center” allowed by ordinance in the district. Abbott v. Bd. of County Comm'rs of Weld County, 895 P.2d 1165 (Colo. App. 1995).   Zoning is a proper exercise of the state's police power. Rademan v. City & County of Denver, 186 Colo. 250 , 526 P.2d 1325 (1974).   The power and force of the police power attends in the regulations provided in zoning ordinances, and the rule is that the doctrine of estoppel does not apply. Flinn v. Treadwell, 120 Colo. 117 , 207 P.2d 967 (1949); Witkin Homes, Inc. v. City & County of Denver, 31 Colo. App. 410, 504 P.2d 1121 (1972).   Certain rights yield to zoning regulations. Even though the right of freedom of association and of privacy are cherished rights, they must yield to valid zoning regulations. Rademan v. City & County of Denver, 186 Colo. 250 , 526 P.2d 1325 (1974).   If necessary to protect compelling and substantial government interest. If a zoning ordinance impinges on fundamental rights, the ordinance may be sustained only upon a showing that the burden imposed is necessary to protect a compelling and substantial government interest. Rademan v. City & County of Denver, 186 Colo. 250 , 526 P.2d 1325 (1974).   Such as to provide for the health, safety, and welfare of its citizens and the general public, a city has the power to classify land within its boundaries for specified uses. Bird v. City of Colo. Springs, 176 Colo. 32 , 489 P.2d 324 (1971).   A zoning ordinance is presumed to be valid and one assailing it bears the burden of overcoming that presumption as the courts indulge in every intendment in favor of the validity of the ordinance. City & County of Denver v. Chuck Ruwart Chevrolet, Inc., 32 Colo. App. 191, 508 P.2d 789 (1973).   Once the power to classify land to specified uses is exercised by a city, it is entitled to a presumption of validity and one assailing it bears the burden of overcoming that presumption, and courts indulge every intendment in favor of its validity. Bird v. City of Colo. Springs, 176 Colo. 32 , 489 P.2d 324 (1971).   Zoning ordinances, like other legislative enactments, are presumed valid. Ford Leasing Dev. Co. v. Bd. of County Comm'rs, 186 Colo. 418 , 528 P.2d 237 (1974).   A home-rule city zoning code is a legislative enactment which is presumed to be valid. City of Greeley v. Ells, 186 Colo. 352 , 527 P.2d 538 (1974).   And one challenging a zoning ordinance has the burden of proving beyond a reasonable doubt that it is invalid. Ford Leasing Dev. Co. v. Bd. of County Comm'rs, 186 Colo. 418 , 528 P.2d 237 (1974).   To overcome the presumption that a city has validly exercised its zoning powers, the one claiming invalidity must establish such invalidity beyond a reasonable doubt. Bird v. City of Colo. Springs, 176 Colo. 32 , 489 P.2d 324 (1971).   In challenging the validity of a zoning ordinance, it is incumbent upon the aggrieved party to establish that as applied to this property, the ordinance is confiscatory and deprives him of the use of his land without due process of law. City & County of Denver v. Chuck Ruwart Chevrolet, Inc., 32 Colo. App. 191, 508 P.2d 789 (1973).   The presumption of validity which a zoning ordinance possesses imposes upon the litigant challenging the ordinance's validity the burden of proving that the ordinance is unconstitutional by “clear and convincing” evidence. City of Greeley v. Ells, 186 Colo. 352 , 527 P.2d 538 (1974).   Substantial compliance with statutory provisions is required for lawful enactment of a zoning change and failure to comply with essential mandates of the statutes invalidates the proceeding. Wainwright v. City of Wheat Ridge, 38 Colo. App. 485, 558 P.2d 1005 (1976).   Factors to be considered in construing ordinance. Because zoning laws should be given a fair and reasonable construction in light of the setting in which employed, the factors surrounding adoption of an ordinance should be considered. Wainwright v. City of Wheat Ridge, 38 Colo. App. 485, 558 P.2d 1005 (1976).   Zoning, since it restricts an owner's right to use his property, constitutes a partial taking, but it is constitutionally permissible, however, so long as it is reasonable. Serv. Oil Co. v. Rhodus, 179 Colo. 335 , 500 P.2d 807 (1972).   And a landowner need not be permitted to make the most profitable use of his land. The due process and just compensation clauses do not require that zoning ordinances permit a landowner to make the most profitable use of his property. Bird v. City of Colo. Springs, 176 Colo. 32 , 489 P.2d 324 (1971); Baum v. City & County of Denver, 147 Colo. 104 , 363 P.2d 688 (1961); Nopro Co. v. Town of Cherry Hills Vill., 180 Colo. 217 , 504 P.2d 344 (1972).   There is simply no constitutionally protected right under the federal or state constitutions to gain the maximum profit from the use of property. Nopro Co. v. Town of Cherry Hills Vill., 180 Colo. 217 , 504 P.2d 344 (1972).   Right to gain maximum profit from use of property not constitutionally protected. There is simply no constitutionally protected right under the federal or state constitutions to gain the maximum profit from the use of property. City & County of Denver v. Chuck Ruwart Chevrolet, Inc., 32 Colo. App. 191, 508 P.2d 789 (1973).   The validity of zoning ordinances has never been determined by the highest and best use concept or in terms of profitability. City & County of Denver v. Chuck Ruwart Chevrolet, Inc., 32 Colo. App. 191, 508 P.2d 789 (1973).   The mere fact that the regulation deprives the property owner of the most profitable use of his property is not necessarily enough to establish the owner's right to compensation. Art Neon Co. v. City & County of Denver, 488 F.2d 118 (10th Cir. 1973), cert. denied, 417 U.S. 932, 94 S. Ct. 2644, 41 L. Ed. 2d 236 (1974).   If the land in question is susceptible to any reasonable or lawful use under the classification imposed by a city, the ordinance will be allowed to stand. Bird v. City of Colo. Springs, 176 Colo. 32 , 489 P.2d 324 (1971); Trans-Robles Corp. v. City of Cherry Hills Vill., 30 Colo. App. 511, 497 P.2d 335 (1972), aff'd, 181 Colo. 356 , 509 P.2d 797 (1973).   Zoning ordinance is unconstitutional if it deprives property owner of any reasonable use to which his land may be put. City of Cherry Hills Vill. v. Trans-Robles Corp., 181 Colo. 356 , 509 P.2d 797 (1973).   A zoning ordinance is unconstitutional if it can be shown that the zoning ordinance precludes the use of property for any reasonable purpose. Ford Leasing Dev. Co. v. Bd. of County Comm'rs, 186 Colo. 418 , 528 P.2d 237 (1974).   In order for the courts to hold a zoning ordinance to be violative of the due process rights of a property owner or to interfere with the discretion of the zoning authorities in drawing zoning boundaries, the person challenging the zoning ordinance must establish beyond any reasonable doubt that the property cannot be devoted to any reasonable lawful use under the challenged ordinance. City & County of Denver v. Chuck Ruwart Chevrolet, Inc., 32 Colo. App. 191, 508 P.2d 789 (1973).   Or if not substantially related to public health, safety, or welfare. A zoning ordinance is unconstitutional if it can be shown that it is not substantially related to the public health, safety, or welfare. Ford Leasing Dev. Co. v. Bd. of County Comm'rs, 186 Colo. 418 , 528 P.2d 237 (1974).   In a challenge to a general zoning ordinance, the outcome turns on the exercise of the police power as bearing a reasonable relation to the public health, safety, morals, or welfare. Snyder v. City of Lakewood, 189 Colo. 421 , 542 P.2d 371 (1975).   Whether zoning provisions are reasonable and for promotion of public health, safety, and welfare, is to be determined by the court from facts, circumstances, and locality in the particular case. Bird v. City of Colo. Springs, 176 Colo. 32 , 489 P.2d 324 (1971).   Group homes permitted in residential neighborhoods as matter of statewide concern. Group homes for developmentally disabled persons are permitted in residential neighborhoods as a matter of statewide concern. Roundup Found., Inc. v. Bd. of Adjustment, 626 P.2d 1154 (Colo. App. 1980).   The general assembly intended that group homes for the developmentally disabled be considered a residential use of property and that they be permitted in all residential zones, specifically including those zoned for single family dwellings. It is inconsistent with this intent for a city council to base its denial of a special use permit on the adverse effects of the group home on the single family characteristics of the neighborhood or on the peace and quiet of the neighborhood, in addition to the attitude of general hostility in the neighborhood towards this proposed facility. Adams County Ass'n for Retarded Citizens, Inc. v. City of Westminster, 196 Colo. 79 , 580 P.2d 1246 (1978).   Although municipalities may regulate certain aspects of construction and location. The general assembly has expressly reserved to municipalities the right to regulate several aspects of the construction and location of group homes in order to avoid adverse impacts on the neighborhood, as long as such regulation is not tantamount to prohibition of such homes within any residential district. Glennon Heights, Inc. v. Central Bank & Trust, 658 P.2d 872 (Colo. 1983).   Zoning not disturbed unless legislative body exceeds powers. Zoning determination cannot be disturbed by the courts unless it appears that the legislative body has exceeded its powers or has acted arbitrarily or unreasonably. City of Greeley v. Ells, 186 Colo. 352 , 527 P.2d 538 (1974).   Proof that it is not possible to use land for any of the uses permitted in the intervening zones between the zone sought and the existing zone is a prerequisite to showing that the property has been unconstitutionally confiscated under existing zoning. Ford Leasing Dev. Co. v. Bd. of County Comm'rs, 186 Colo. 418 , 528 P.2d 237 (1974).   When a city annexes land from a county, the power to zone that land shifts to the city. Bird v. City of Colo. Springs, 176 Colo. 32 , 489 P.2d 324 (1971).   For issuance of writ of mandamus to compel issuance of building permit where zoning ordinance is unconstitutional, see Hedgcock v. People ex rel. Arden Realty & Inv. Co., 98 Colo. 522 , 57 P.2d 891 (1936).   Property owners have the right to rely on existing zoning regulations where there has been no material change in the character of the neighborhood which may require rezoning in the public interest. Roosevelt v. Beau Monde Co., 152 Colo. 567 , 384 P.2d 96 (1963).   Applicability of estoppel. To invoke the doctrine of equitable estoppel in relation to a zoning ordinance, the plaintiff must show substantial reliance upon the zoning ordinance and mere procurement of a building permit is insufficient. Witkin Homes, Inc. v. City & County of Denver, 31 Colo. App. 410, 504 P.2d 1121 (1972).   Party seeking application of doctrine of equitable estoppel to government action must show reasonable reliance. Bentley v. Valco, Inc., 741 P.2d 1246 (Colo. App. 1987).   In order to invoke the doctrine of equitable estoppel against a city in relation to a zoning ordinance, the plaintiff must show as a factual predicate that there was a communication or action by the city by which he was unmistakably misled. LaFollette v. Bd. of Adj. of Lakewood, 741 P.2d 1262 (Colo. App. 1987).   A party cannot state a claim for relief under a theory of estoppel against a state or local government entity on the basis of an unauthorized action or promise. Lehman v. City of Louisville, 967 F.2d 1474 (10th Cir. 1992).   Zoning changes should be placed on map as soon as possible. As soon as reasonably possible after adoption by the board of county commissioners of changes in zoning, they should be placed upon an authorized copy of an original map or maps with the date of the action shown along with the type of change. Wainwright v. City of Wheat Ridge, 38 Colo. App. 485, 558 P.2d 1005 (1976).   A zoning map merely reflects the effect of exercises of the zoning power. Wainwright v. City of Wheat Ridge, 38 Colo. App. 485, 558 P.2d 1005 (1976).   And changes made thereon do not of themselves constitute an exercise of that power. Wainwright v. City of Wheat Ridge, 38 Colo. App. 485, 558 P.2d 1005 (1976).   Since there was no resolution by the board of county commissioners amending a zoning map, the inadvertent or erroneous change in the zoning map was without effect. Wainwright v. City of Wheat Ridge, 38 Colo. App. 485, 558 P.2d 1005 (1976).   Status of county zoning at time map incorporated governs. Inasmuch as zoning maps derive their effectiveness from the ordinance or resolution that adopts them, it is the status of the county zoning, at the time the city incorporated the map into its zoning ordinance, that governs. Wainwright v. City of Wheat Ridge, 38 Colo. App. 485, 558 P.2d 1005 (1976).   A zoning resolution may legally restrict the right of a landowner to extend or enlarge a nonconforming use. Bird v. City of Colo. Springs, 176 Colo. 32 , 489 P.2d 324 (1971).   A city council, in the exercise of its police power, must afford procedural due process as it has been delineated in its zoning code. McArthur v. Zabka, 177 Colo. 337 , 494 P.2d 89 (1972).   Zoning proceedings are informal in nature and do not require application of the rules of evidence used in judicial proceedings. The primary requirement is that the principles of fundamental fairness be observed in such proceedings. Nat'l Heritage, Inc. v. Pritza, 728 P.2d 737 (Colo. App. 1986).   Regulation of signs permitted. The powers granted to a statutory city by this section and § 31-15-103 are commodious enough to enable it to promote its safety and aesthetic interests by regulating the number and type of signs permitted in different zoning districts. City of Lakewood v. Colfax Unlimited Ass'n, 634 P.2d 52 (Colo. 1981).   Federal highway beautification act and Colorado highway sign act have not preempted cities in regulation of signs nor do they bind the cities by example or standard. Art Neon Co. v. City & County of Denver, 488 F.2d 118 (10th Cir. 1973), cert. denied, 417 U.S. 932, 94 S. Ct. 2644, 41 L. Ed. 2d 236 (1974).   Requirements for sustaining denial of special exception to floodplain ordinance. Where a city council is acting in an adjudicative capacity with respect to an application for a special exception to a floodplain ordinance, the following would be required to sustain a denial of the application: If there is a lack of evidence to show that certain of the required factors existed, or if the evidence is in dispute as to one or more of these factors, and the city council determines the application should be denied, then it would have to make specific findings of fact as to what factors were or were not established. Bauer v. City of Wheat Ridge, 182 Colo. 324 , 513 P.2d 203 (1973).   And only factors which apply to all applicants may be considered. Where city enacted a floodplain ordinance, and the ordinance establishes the criteria upon which a “special exception” will be granted, if the city council believes that other reasons should be used in denying an application for the exception, then the appropriate procedure is to amend the floodplain ordinance, for once an applicant applies under the ordinance, only those factors which apply generally to all applicants may be considered. Bauer v. City of Wheat Ridge, 182 Colo. 324 , 513 P.2d 203 (1973).   Construction of ambiguous ordinance. The testimony of the zoning administrator, who dealt with a zoning ordinance on a day-to-day basis, is significant in construing ambiguous language in the ordinance. Humana, Inc. v. Bd. of Adjustment, 189 Colo. 79 , 537 P.2d 741 (1975).   Meaning of “structure”. A parking lot is a “structure” within the meaning of this section. Clark v. Town of Estes Park, 686 P.2d 777 (Colo. 1984).   Time limit for judicial review. Since the municipal zoning statutes do not specify a time limit for judicial review, the 30-day time frame in C.R.C.P. 106(b) is applicable. Norby v. City of Boulder, 195 Colo. 231 , 577 P.2d 277 (1978).   Applied in Wood Bros. Homes v. City of Colo. Springs, 42 Colo. App. 15, 592 P.2d 1336 (1978).