Primary conservation areas - MRCCA

collage of shorelines

Primary conservation areas (PCAs) are natural and cultural resources identified in the 2017 MRCCA rules and in local MRCCA plans . The rules (and local zoning regulations that comply with the rules) protect PCAs from development, vegetation removal, and land alteration activities. This page explains these resources, why they are important, and common local regulations that apply.

Note! Standards pertaining to PCAs only apply to the communities that have adopted new MRCCA zoning regulations consistent with the 2017 MRCCA rules. These communities are listed on the Property owner information page.

What are primary conservation areas (PCAs) and why are they important? 

Common PCAs

You can determine what common PCAs are on your property by using the Primary Conservation Area Mapping Application. Following is a description of common PCAs and why they are important: 

Shore impact zones (SIZ)

The SIZ is a strip of land along rivers. The depth of the strip is 50% of the required structure setback from the river – described as the “ordinary high water level (OHWL) setback” in the MRCCA rules and local zoning regulations. The width of the SIZ varies depending on the MRCCA district. See the MRCCA District Mapping Application to see what district you are in.

The SIZ is an environmentally sensitive area that, when naturally vegetated, provides wildlife habitat and safe movement corridor to a wide variety of animal species. The SIZ provides room for deep-rooted natural vegetation that stabilizes soils and reduces bank erosion, and slows and infiltrates runoff, reducing the flow of pollution-causing nutrients and sediment into the river. A naturally vegetated SIZ also provides a natural defense against invasive species, and maintains and enhances the scenic quality of the river.


Bluff impact zones (BIZ)

The BIZ includes bluffs and land within 20 feet of bluffs. Bluffs are features that have a slope of 18% or greater. 

Many bluffs are fragile areas subject to erosion and/or failure when exposed to stresses such as construction activities, stormwater runoff, structure placement, vegetation removal, and land alteration. Naturally vegetated bluffs also provide wildlife habitat and enhance the scenic quality of the river. To learn more about strategies for reducing risk of slope failure and tools for identifying slopes, see the Bluff and Slope Protection webpage.



Floodplains are areas adjoining waterbodies or watercourses that have or may be covered by regional floods. These areas have been mapped by the Federal Emergency Management Agency (FEMA).

Keeping structures and filling activities out of the floodplain reduces the risk of flood damage and loss, and allows for critical storage of floodwaters


Wetlands are transitional lands between terrestrial and aquatic systems where the water table is usually at or near the surface or land covered by shallow water.

Wetlands are critical wildlife habitat for many animal species. They filter pollution-causing nutrients and hold water, reducing flooding elsewhere.

Native plant communities

These are plant communities of five acres or greater that meet the quality criteria established by the Minnesota Biological Survey to qualify as a native plant community.

Native plant communities provide wildlife habitat for many endangered and threatened animal and plant species, including pollinators. The long-term survival and viability of many of these species depends on native plant communities. 

Significant existing vegetative stands

These are largely intact and connected plant communities that contain a sufficient representation of the original native plant community. 

This vegetation also provides habitat for endangered and threatened plant species but within a vegetated corridor that is larger and more continuous than that typical with the few remaining native plant communities. These corridors help plants and animals naturally spread and disperse. This is especially important to protect as development fragments habitat, climate change accelerates, and invasive species increase. In addition, these vegetation areas serve as living remnants of the original native communities that existed in the corridor, even though they do not meet the size and quality criteria to be classified as a Native Plant Community by the MBS.

Less common PCAs

Following are less common PCAs that may not exist in all communities and are not shown in the mapping application. Check with your local government to see if any of these PCAs apply to your property:

Cultural and historic properties

These sites are listed in the National Register of Historic places and include historic landmarks and districts as well as those eligible for national historic status and sites identified as having local cultural or historical significance.

River Gorge

The gorge is generally located between St. Anthony Falls in Minneapolis and the High Bridge in St. Paul.

Areas of River Confluence

These are floodplain areas at the confluences of the Mississippi River with the Crow, Rum, Minnesota, and Vermillion rivers. 

Natural drainage ways

These include rivers and streams and any other drainage ways identified by local governments.

Unstable soils and bedrock

These are known or probable areas of unstable soils and bedrock.

What does it mean if a PCA exists on my property? 

If one or more PCAs exist on your property, you will need to ensure that any future construction, landscaping, or land alteration activities comply with the PCA protective standards and permit requirements in your local MRCCA zoning regulations. These standards and permit requirements are summarized below and organized according to typical property owner activities/applications (specific PCAs are italicized).  

All development applications 
  • Project description: All applications, including variances, CUPs, building, vegetation management, and land alteration, must include a detailed project description.
  • Information on PCAs: Site plans and maps submitted with any permit application must show the type and location of all PCAs on your property.
Building and construction standards 

Creating new lots:

All new lots must have an adequate buildable area so as to not require variances to use lots for their intended purpose. Buildable area cannot include land needed to  meet setbacks, rights-of-way, bluff impact zones, historic properties, and wetlands, floodways, and land below the ordinary high water level.

Standards for all structures: 

  • All structures placed in the floodplain must meet the standards in the local government’s floodplain ordinance.
  • Structures, including decks and patios, must not be placed in the shore impact zone or the bluff impact zone

Expanding nonconforming structures:

Nonconforming principal structures may be expanded laterally as long as the expansion does not extend into the shore impact zone or the bluff impact zone.

Water oriented accessory structures:

Water-oriented accessory structures are:

  • prohibited in the bluff impact zone.
  • Allowed in the shore impact zone but must:
    • Not exceed 12 feet in height
    • Not exceed 120 square feet; and
    •  Be placed at least 10 feet from the ordinary high water level. 

Standards for all impervious surfaces:

Private driveways, parking areas and other impervious surfaces must not be placed in the shore impact zone or the bluff impact zone.

Access paths:

Access paths can be no wider than 8 feet wide in the shore impact zone or 4 feet wide in a bluff impact zone.

Temporary storage:

Temporary storage of docks, boats, and other equipment during the winter months are prohibited in the bluff impact zone but allowed in the shore impact zone.

Stairways, lifts, and landings:

Stairways, lifts, and landings are allowed in the shore impact zone and the bluff impact zone as long as stairways and lifts are no wider than 4 feet and landings no more than 32 square feet.

Vegetation removal and management standards and permit requirements

Vegetation removal requiring a permit:

Intensive vegetation clearing in the shore impact zone, bluff impact zone, within 50 feet of a wetland or natural drainage way or intensive clearing of native plant communities and significant existing vegetative stands is prohibited except the following activities with a vegetation permit:

  • Clearing of vegetation that is dead, diseased, dying, or hazardous;
  • Clearing to prevent the spread of diseases or insect pests;
  • Clearing to remove invasive non-native species;
  • Clearing to prepare for restoration and erosion control management activities consistent with a plan approved by the local government; 
  • The minimum necessary for development that is allowed with a building permit.

As a condition of vegetation permit approval:

  • Removal of any native plant communities must be replaced with equivalent vegetation consistent with a local government-approved vegetation restoration plan.
  • Removal of all other vegetation, including significant existing vegetative stands must be restored with natural vegetation to the greatest extent practicable consistent with a local government-approved vegetation restoration plan.

Landscaping and maintenance not requiring a permit:

On properties containing PCAs, the following activities are allowed without a vegetation permit:

Maintenance of existing lawns, landscaping and gardens; Selective vegetation removal within areas identified with native plant communities and significant existing vegetation:

  • Of vegetation that is dead, diseased, dying or hazardous;
  • Of invasive non-native species;
  • Of individual trees and shrubs;
  • To prevent the spread of diseases or insect pests.
Land alteration and stormwater standards permitting requirements

Alterations in the SIZ:

Land disturbance of more than 10 cubic yards or more than 1,000 square feet requires a land alteration permit in the shore impact zone or within 50 feet of the ordinary high water level (OHWL), whichever is less.  

Alterations in the BIZ:

Land alteration is prohibited in the bluff impact zone except for erosion control projects and the repair and maintenance of existing buildings with a land alteration permit.

Alterations of wetlands:

Alteration of wetlands must meet standards in the local government’s wetland ordinance.

Rock riprap, retaining walls, and other erosion control structures:

Construction or replacement of rock riprap, retaining walls and other erosion control structures are allowed in the bluff impact zone and shore impact zone (and water quality impact zone) with a land alteration permit consistent with specific design standards and conditions.

Stormwater facilities:

Stormwater facilities, including rain gardens, are prohibited in the bluff impact zone, except with a land alteration or stormwater permit.

Variances and conditional use permits (CUPs)

Potential impacts:

Potential impacts of the proposed variance or CUP to all PCAs are evaluated by local government staff and/or the planning commission.

Conditions of approval:

If negative impacts are found and the application is approved, then measures to offset the impacts will be conditions of approval. Local governments may require the restoration of vegetation that has been identified as “vegetation restoration priorities” in its MRCCA plan. 

Note: This is not a complete list or description of all MRCCA zoning standards. Check with your local government to review and understand ALL applicable regulations and permits.

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