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Stream Buffers and Setbacks Model and Commentary

Model Code

In drafting and adopting riparian buffer and setback requirements, four issues should be considered:

  • Purpose and intent
  • Applicability and exemptions
  • Development standards
  • Procedures

Each of these is described in further detail below, including model language in beige shading for consideration. Commentary is located in the column at the right. The model language used in this document is based on several existing ordinances from varying communities around the state, including municipalities and counties. The language is illustrative only; consult local counsel to tailor language for your jurisdiction.

Commentary

Location of Riparian Buffer and Setback Regulations: Floodplain regulations are often included in zoning ordinances as a standalone chapter or article. They tend to be based largely on CWCB model regulations. Due to their length, specificity, and unique applications, they typically remain separate from other standards rather than being woven into other setbacks, use-specific standards, or permitting procedures.

Purpose and Intent

This section should describe the jurisdiction’s intent in adopting buffers, setbacks, and/or other riparian protection standards. Common purposes include:

  1. To promote, preserve, and enhance the hydrologic, biological, ecological, aesthetic, recreational, and educational functions that stream and river corridors, associated riparian areas, and wetlands provide;
  2. To identify flood hazards and avoid development within those flood hazards to the extent practicable;
  3. To establish regulations seeking maximum protection of all waters of [name of jurisdiction];
  4. To avoid development activity within [buffer zones];
  5. To minimize the adverse impacts of development activity within [buffer zones];
  6. To mitigate the impacts of development within [buffer zones];
  7. To subject development within [buffer zones] to heightened review;
  8. To prevent property loss and loss of life while ensuring the natural and unimpeded flow of watercourses; and
  9. To encourage development and land uses that preserve existing watercourses as important natural features.

Purpose and Intent: The purpose and intent statement will vary depending on the types of watercourses and riparian areas the community is trying to protect. Communities should try to integrate established policies from the local hazard mitigation plan, the comprehensive plan, and other adopted policies and regulations where possible.

Applicability and Exemptions

Applicability standards describe when the riparian buffers and setback standards apply, and if there are any types of development activities or land uses that are exempt from the standards. The applicability section should include the following provisions:

  1. The provisions of this [chapter/article/section] apply to all development within [100 feet] from the high-water line of the [name of watercourse(s)] and to all development within the 100-year floodplain.
  2. This section shall apply to all new development, except for the following:
    1. The development does not add more than [ten percent, or desired percentage] to the floor area;
    2. No portion of the expansion, remodeling, or reconstruction will be closer to the high water line than the current development; and
    3. The expansion, remodeling, or reconstruction shall not constitute a substantial improvement in terms of floodplain regulation, and shall not increase the amount of ground coverage of structures within the 100-year floodplain.
    4. Maintenance and repair of existing public roads and utilities within easements or public rights-of-way;
      1. Maintenance and repair of flood control structures;
      2. Emergency response activities following a flooding event;
      3. The expansion, remodeling, or reconstruction of an existing development provided the following standards are met:

Expansion, Remodeling, or Reconstruction:  Expansions of current structures or uses within designated floodplains or stream buffers require consideration of appropriate thresholds. For example, what if a roof needs replacement? What if a deck is proposed? What if the expansion is upward and does not expand the footprint? 

Development Standards

Standards for riparian buffers and setbacks vary widely; however, general approaches to managing development within stream buffers include the following:

  1. Development within the required buffer zone shall not be permitted unless the proposed development:
    1. Is required to provide protection against property loss and/or damage;
    2. Will improve the quality of the [name or type of watercourse, or buffer zone] and enhance the ecosystem by improving water quality, wildlife habitat, or biodiversity;
    3. Will not increase the base flood elevation on the parcel; and
    4. Will not pollute or interfere with the natural changes of the river, stream, or other tributary, including erosion and sedimentation during construction.
  2. There shall be no development below the top of slope or within [15 feet] of the top of slope or the high waterline, whichever is more restrictive;
  3. No development or use shall be permitted that will disturb, remove, fill, drain, dredge, clear, destroy, or alter any area, including vegetation, within stream or river corridors, wetlands, or their associated [buffer/setback areas] unless expressly allowed by this [code/ordinance].
  4. No fill material or debris shall be placed on the face of the slope in a stream buffer, and historic drainage patterns and rates shall be maintained;
  5. Parking lots shall be setback a minimum of [15 feet] from the top of slope;
  6. All buildings, accessory structures, and parking lots shall be setback a minimum of [50 feet] from the delineated edge of any wetland; and
  7. If development in a [buffer zone/setback area] causes any disturbance within the [buffer zone/setback area], the applicant shall undertake restoration and mitigation measures such as regarding and revegetation to restore any damaged or lost natural resource.

Development Standards: Depending on the chosen standards, communities can apply them so that all standards have to be met or that a defined number of standards have to be met. For example, the community could state that “development shall not be approved in the buffer zone unless at least two of the following standards are met.”

Top of Slope Limitation: This standard is developed to protect bank stability and riparian vegetation.

Procedures

When development is proposed in areas where riparian buffers and setbacks apply, additional procedural requirements often apply. For example, a special use review application might not ordinarily require a grading plan; however, if the property contains a designated watercourse, then the community may require delineation of grades at two-foot contours. The specific procedural adjustments vary depending on the type of development and the type of approval being sought.

The following are examples of the types of supplemental procedures that may apply to development subject to riparian buffers and setbacks:

  1. The development application shall include the following:
    1. Existing and proposed grades at two-foot contours;
    2. Proposed elevations of the development;
    3. Delineation of the high water line and the 100-year floodplain; and
    4. A description of the proposed construction techniques, including for grading, erosion, and sediment control.
  2. B. The [Director/Administrator] may recommend and the [Planning Commission/City Council/Board of County Commissioners, or equivalent] may impose conditions to approval of an application with stream buffers and setbacks that include:
    1. Minimizing adverse impacts of the proposed development including the operation, type, and intensity of land uses;
    2. Controlling the timing of the proposed development;
    3. Controlling the duration of use of the development and the time in which structures must be removed; and
    4. Assuring that development is maintained properly over time.

Procedures: Approval procedures in a zoning code will likely already be defined in a separate administration and procedures chapter or section. These additional procedures would apply above and beyond those required for a development that is not subject to riparian buffers and setbacks. Additional procedures that apply in hazard-prone areas often build on and cross-reference the common review procedures that apply to all development applications.

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