Table of Contents
For any type of development project, most communities have standard rules that control the format and contents of applications. For example, communities specify the type and format of plans required, along with the number of copies needed for supporting documents like maps. Applicants must indicate which local code requirements are applicable to their project, and how they meet the criteria for approval. Applications must be accompanied by required fees, proof of ownership, and contain authorized signatures. Application submittal requirements are typically found with each specific procedure in the zoning ordinance. However, they are often located outside the zoning ordinance and included in an administrative manual or on the local government website. That allows staff to update the application submittal requirements without amending the ordinance.
In addition to these general requirements, applications for projects in hazard-prone areas should be required to include additional materials and/or complete additional steps that are tailored to local conditions and the natural hazard being regulated. These may include:
- Attendance at a pre-application meeting;
- Completion of a site visit;
- Preparation of a site-specific natural hazards map;
- Submission of technical reports; and
- Development of a mitigation plan.
Ideally, submittal requirements should be developed collaboratively by all agencies that will be involved in the ultimate review of the application. Agencies such as the local fire district or flood management agency should be consulted in the initial development of the community’s application requirements for projects in hazard-prone areas.
The following sections describe each of these elements and provide standard language that can be considered by Colorado local governments. Model language is in gray shading. Commentary is located in italics in the column at the right. The model language used in this document is based on several existing ordinances and programs from varying communities around the state, including municipalities and counties. The language is illustrative only; consult local counsel to tailor language for your jurisdiction.
Pre-Application Meeting: The pre-application meeting is an important tool to make sure the applicant is aware that natural hazards may affect the subject property and to identify gaps in the hazard-related information currently available in official maps and reports. Not all hazards can be mapped, but those commonly mapped include flood hazards, wildfire hazards, geologic hazards (landslides, rockfall, and subsidence), avalanche areas, fault zones (earthquake), and hazardous material areas. Applicants can also find hazard maps in the Local Hazard Mitigation Plan, or sometimes in the Comprehensive Plan.
The meeting also is an opportunity for the applicant and staff to discuss the specific local ordinance requirements that will apply to the development.
The language below is a good example of where hazard area maps are called out specifically. This shows the applicant that hazard mitigation and avoidance are critical to the development review process.
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A pre-application meeting is required prior to submitting an application for development. Prior to the pre-application meeting, the applicant should consult the official hazard area maps available in the Planning Department to identify any potential hazard areas on the proposed development site.
- The applicant shall submit a brief description of the existing land use of the site and of the proposed land use and an informal sketch of the existing site prior to the pre-application meeting. The sketch shall show the total acreage of the site, land owners, land uses, streets, highways, utilities, major physical features (rock outcroppings, drainages, etc.), and the location of natural hazards.
- At the pre-application meeting, planning staff will assist the applicant to determine if a hazard area exists on the property and explain the relevant procedures for review if a hazard area is identified.
- At the pre-application meeting, planning staff will provide the applicant with a list of the documents, maps, and technical reports required for the application.
- Following the pre-application meeting, a site visit may be scheduled for planning staff to meet with the applicant at the proposed development site.
When hazards are identified on a development site, a site visit shall be conducted by planning staff to verify the information on the official hazard maps, review the information required for the application process, and discuss mitigation requirements with the applicant.
Site Visit: Technical staff knowledgeable in the natural hazard may be referenced and included in a site visit to provide more detailed information about mitigation and requirements.
For all development proposals or land use activities on a site where a natural hazard is identified at the pre-application meeting and confirmed during the site visit, a site map prepared by a licensed geologist or engineer depicting the extent and severity of all identified natural hazards shall be submitted by the applicant to the Planning Department. The site map shall show the extent and severity of the hazard(s) at the particular site. Maps shall be produced at a scale sufficient to determine the nature, extent and severity of the natural hazard. If needed, cross-sections can be used to portray the hazard conditions.
Technical Specialists Should Prepare Maps: A professional engineer and/or geologist should prepare all maps and technical reports describing and evaluating natural hazards. It is typical for the type of engineer to be specified in the code (e.g., geotechnical engineer for reports on a geologic hazard area). For wildfire hazard reports, a professional forester is usually required to prepare the documents.
The local ordinance should specify the types of technical reports and documentation that are necessary to determine the extent of potentially hazardous conditions on the site, the exposure of the site to off-site hazards that could damage land uses on the site, and the risk of causing damage to adjacent properties because of disturbance to the site. The information contained in such reports should be presented clearly and be based on technical site-specific data and surveys. The report should address the potential effects of the hazards on the proposed development in terms of risk and potential damage. Below is a generalized example of the type of technical reports that could be required for review of development in a natural hazard area.
Technical reports prepared by professional engineers and/or geologists are required for all development applications on a site in an identified natural hazard area. Reports and studies required to evaluate the development in the context of known natural hazards will be determined by the Planning Director in conjunction with the Building Official and Fire District Official. Technical reports may be forwarded to professional experts for review and recommendation. The following information may be required based on the pre-application meeting, the site characteristics, type of development proposed, surrounding land use, and environmental conditions.
A. Geologic Hazard Report
- An index map showing the general location of the development area and its relationship to surrounding topographic features.
- A map showing the location, nature, and density of the proposed development or land use activity. The map should be at a scale sufficiently detailed to meet the objectives to evaluate the scope of the geologic hazard in relation to the development.
- On-site soils investigation if in a soils hazard area.
- Geologic hazard map showing geologic, hydrologic, soil, and topographic features relating to the geologic hazard and geologic cross-sections if needed.
- Site history describing any prior grading, soil instability, or slope failure.
- A site evaluation explaining all maps and technical data and describing the suitability of the site to accommodate the proposed development or land use activity.
B. Wildfire Hazard Report
- A map showing the extent and severity of the wildfire hazard at the particular site.
- A site map showing existing vegetation on the site.
- A site evaluation describing the potential for wildfire on the site and the potential for wildfire to spread from the site to surrounding property and vegetation.
C. Flood Hazard Report
- A report detailing all hydrologic and hydraulic calculations used in preparing maps and plans, or an acceptable floodplain study report prepared by a recognized agency such as the Federal Insurance Administration or Colorado Water Conservation Board (CWCB).
- Elevation (in relation to mean sea level) of the lowest floor (including basement) of all new and substantially improved structures.
- Elevation (in relation to mean sea level) to which any nonresidential structure shall be floodproofed.
- A certificate from a registered Colorado Professional Engineer or architect that the nonresidential floodproofed structure shall meet the floodproofing criteria contained in the development standards section of this code.
Technical Reports: Some communities include a list of very specific technical data requirements in the zoning code itself. Another, more common approach is identify technical reports in a general way in the zoning ordinance and remove specific details (such as scale requirements for maps) to an administrative manual, user’s guide, or handouts outside the code. This allows the technical specifications to be updated and kept current by staff without having to make frequent ordinance amendments.
Smaller communities with limited staff can work with local subject matter experts or other jurisdictions (such as the County or the Colorado Geologic Survey) to determine whether technical reports should be required as part of a development application.
A mitigation plan identifies specific recommendations for the development of a site in a natural hazard area to reduce the risk from the identified natural hazard. These may include building construction techniques and building material specifications. They may direct site layout and installation of landscaping and vegetation or other on-site mitigation measures (such as placement of water cisterns in wildfire hazards). Mitigation plans are usually prepared as part of the technical reports described above. The site plan and accompanying development agreements for the proposed development must incorporate the mitigation plan in order for the development to be permitted.
Examples of mitigation plans vary widely by community, by type of hazard, and by type of development. Reviewing authorities frequently require additional site-specific mitigation techniques to be added to a mitigation plan prior to approving the development. Below are two examples of the type of information that could be required in a mitigation plan.
Mitigation Plans: Mitigation plans should be made part of the development approval, either through recordation of the plan or inclusion of the plan requirements in required site plans or development agreements. Or they may end up being included in other approval instruments, such as a condition of approval in a Board of County Commissioners or City Council resolution.
A. Wildfire Hazard Mitigation Plan
When new development or land use activity is proposed within a wildfire hazard area, the applicant shall be required to submit a mitigation plan addressing how the development or subdivision will either avoid or mitigate the hazard, as more fully set forth below.
- Mitigation plans shall be prepared by a professional forester according to generally accepted wildland-urban interface protection standards.
- The mitigation plan shall recommend how to design, manage, and maintain the proposed development or land use activity to adequately mitigate wildfire hazard, including any mitigation for construction activities. The plan shall describe how the recommendations reduce wildfire hazard levels.
- The plan shall address site vegetation as well as existing and proposed on-site structures, access and emergency fire access.
- Mitigation methods may include, but are not limited to:
a. Specific requirements for construction, location and density of structures and lots;
b. Provision of defensible space;
c. Specific requirements for alteration to the vegetative features of the land; and
d. Specific requirements for emergency access and water system capacity.
B. Geologic Hazard Mitigation Plan
When new development or land use activity is proposed within a geologic hazard area, the applicant shall be required to submit a mitigation plan addressing how the development or land use activity will either avoid or mitigate the hazard, as more fully set forth below. Licensed professional engineers and/or geologists who are experienced in the engineering specialty (e.g., soils, slope stability) may submit mitigation plans for steep slope and alluvial soils hazards.
- The mitigation plan shall be prepared by a professional geologist and shall recommend how to design, manage, and maintain the proposed development or land use activity to adequately mitigate the geologic hazard(s), including any mitigation for construction activities.
- The plan shall address how the recommendations reduce geologic hazard risks both on and off-site.
- Alternatives and solutions to abate and/or minimize the adverse geologic hazard conditions on structures, utilities, and roads shall be included in the plan.
- Mitigation methods may include, but are not limited to:
a. Avoidance of run-out zones in rock fall hazard areas;
b. Specific requirements for construction, location, density of structures and/or lots;
c. Specific requirements for construction of roads; and
d. Specific requirements for grading and alteration to the physical characteristics of the land.
e. Mitigation techniques recommended by the Colorado Geological Survey and as published in "Guidelines and Criteria for Identification and Land Use Controls of Geologic Hazard and Mineral Resource Areas, 1974.”
Other Sources for Mitigation Information: If the community does not have adopted mitigation or development standards for natural hazard areas, other recognized sources can be referenced. Several communities rely on standards and guidelines published by the Colorado State Forest Service and Colorado Geological Survey for development standards in wildfire and geologic hazard areas.