Minnesota’s shoreland and river-related land use programs regulate development on and near bluffs. Regulations vary slightly for each program and address structure setback, vegetation removal and land alterations. These programs include the Shoreland, Wild and Scenic River, St. Croix Riverway, and the Mississippi River Corridor Critical Area.
Bluff setback standards in these programs help to minimize visual impacts from structures and to provide “general” slope protection from construction activities. These minimum setback standards do not provide sufficient protection for structures adjacent to geologically and hydrologically unstable slopes and stream banks. In these areas, communities are encouraged to adopt stricter standards to protect human safety and property in a reasonable manner.
Following is a summary of the state required minimum bluff protection standards for each of these regulatory programs. These programs are administered by local governments through their zoning ordinances. Local standards may differ from these state required minimum standards.
Shoreland
The statewide shoreland district includes land within 1,000 feet of a public water body or 300 feet of a public water river or stream, or the landward extent of their floodplains. Only land around public waters with a shoreland classification are regulated.
Shoreland Management Program
- Bluff Definitions
"Bluff":
- Part or all of the feature is located in a shoreland area;
- The slope must drain toward the waterbody;
- The slope rises at least 25 feet above ordinary high water level;
- The grade of the slope from the toe of the bluff to a point 25 feet or more above the ordinary high water level averages 30 percent or greater (see figure 1), except that an area with an average slope of less than 18 percent over a distance of at least 50 feet shall not be considered part of the bluff (see figure 2).
Figure 1. Illustration of Bluff
Figure 2. Exception to Bluff
"Bluff Impact Zone": A bluff and land located within 20 feet of the bluff. See Figure 2 for natural escarpment or cliff example and Figure 3 for more common bluff example.
Figure 3. Bluff Impact Zone and Top of Bluff
"Toe of Bluff": the lower point of a 50-foot segment with an average slope exceeding 18 percent or the ordinary high water level (OHWL), whichever is higher.
"Top of Bluff": the higher point of a 50-foot segment with an average slope exceeding 18 percent.
"Steep Slopes": lands having average slopes over 12 percent, as measured over horizontal distances of 50 feet or more, that are not bluffs.
- Bluff setback standards
Structure setbacks must be at least 30 feet from top of bluff
Soil erosion impacts and visibility impacts must be considered before issuing a permit for construction on steep slopes. When determined necessary, local governments must impose appropriate conditions.
- Standards for vegetation management
Intensive vegetation clearing in the shore and bluff impact zones and on steep slopes is prohibited.
Limited clearing and trimming of trees and shrubs in the shore and bluff impact zones and on steep slopes, is allowed to provide a view to the water from the principal dwelling and to accommodate the placement of stairways and landings, picnic areas, access paths, livestock watering areas, beach and watercraft access areas, and permitted water-oriented accessory structures or facilities.
- Standards for land alteration
To limit the amount of erosion and sediment during construction, a grading and filling permit is required for the movement of more than ten (10) cubic yards of material on steep slopes or within shore or bluff impact zones or more than 50 cubic yards in other areas of the shoreland district.
Mississippi River Corridor Critical Area (MRCCA)
The MRCCA follows a 72-mile stretch of the Mississippi River through the seven-county metro area. Land within the MRCCA is defined by a legal description and by districts within the legal boundary. The MRCCA boundary and districts may be viewed using the MRCCA district mapping application
- Bluff definitions
"Bluff:"" a natural topographic feature either of the following:
- A slope that rises at least 25 feet where the grade of the slope averages 18 percent or greater, measured over any horizontal distance of 25 feet, from the toe of the slope to the top of the slope. Where the slope begins below the ordinary high water level, the ordinary high water level is the toe of the slope (see figure 1); or
Figure 1. Bluff
- a natural escarpment or cliff with a slope that rises at least ten feet above the OHWL or toe of the slope, whichever is applicable, to the top of the slope, with a slope of 75 degrees or greater (see figure 2).
Figure 2. Natural Escarpment Bluff and Bluff Impact Zone
"Bluff Impact Zone": A bluff and land located within 20 feet of the bluff. See Figure 2 for natural escarpment or cliff example and Figure 3 for more common bluff example.
Figure 3. Bluff Impact Zone, Bluffline, Toe of Bluff and Top of Bluff
"Bluffline": a line delineating the top of the bluff. More than one bluffline may be encountered proceeding landward from the river (see figures 2 for natural escarpment or cliff example and figure 3 for more common bluff example)
"Toe of the bluff": a line along the bottom of a bluff, requiring field verification, such that the slope above the line exceeds 18 percent and the slope below the line is 18 percent or less, measured over a horizontal distance of 25 feet (see figure 2 for natural escarpment or cliff example and figure 3 for more common bluff example).
"Top of the bluff":a line along the top of a bluff, requiring field verification, such that the slope below the line exceeds 18 percent and the slope above the line is 18 percent or less, measured over a horizontal distance of 25 feet (see figure 2 for natural escarpment or cliff example and figure 3 for more common bluff example).
- Bluff setback standards
Structure setbacks from bluffline vary by district:
- Rural Open Space District: 100 feet
- All other districts: 40 feet
- Standards for vegetation management
- A vegetation management permit is required for any intensive vegetation removal in the following sensitive resource areas: bluff impact zones, shore impact zone, areas within 50 feet of a wetland or natural drainage way and areas containing native plant communities and significant existing vegetative stands. Intensive vegetation removal is the removal of all or a majority of the trees or shrubs in a contiguous patch, strip, row, or block.
- Selective vegetation removal is allowed without a permit in sensitive resource areas. Selective removal is removing isolated individual trees or shrubs that are not in a contiguous patch, strip, row, or block and does not substantially reduce the tree canopy or understory cover.
- Standards for land alteration
Land alteration is prohibited in the bluff impact zone, except for erosion control projects, repair and maintenance of existing structures, stormwater facilities, and construction or replacement of riprap, retaining walls and other erosion control facilities, which require a local permit.
Wild, Scenic and Recreational Rivers
Land within the Wild, Scenic, and Recreational River area is defined by legal descriptions along the Kettle, Mississippi, Minnesota, Rum, Canon, and North Fork of Crow Rivers, and by three districts within the legal boundaries. The Wild, Scenic, and Recreational boundaries and districts may be mapped using the “Minnesota Wild and Scenic Rivers Districts” dataset on MNGEO.
Minnesota's Wild & Scenic Rivers Program.
- Bluff definitions
"Bluffline": a line along the top of a slope connecting the points at which the slope becomes less than 13 percent.
- Bluff setback standards
Structure setbacks from a bluffline vary by District:
- Wild River Districts: 40 feet
- Scenic River Districts: 30 feet
- Recreational River Districts: 20 feet
- Standards for vegetation management
Selective cutting of trees in excess of four inches at breast height is allowed if cutting is spaced and a continuous tree cover is maintained. Clear cutting, except for public services such as roads and utilities, is not permitted within:
- The following distances from the Normal High Water Mark:
- Wild River Districts: 200 feet
- Scenic River Districts: 150 feet
- Recreational River Districts: 100 feet
- Designated Tributaries of wild, scenic and recreational rivers identified in rules: 100 ft
- The following distances from blufflines:
- Wild River Districts: 40 feet
- Scenic River Districts: 30 feet
- Recreational River Districts: 30 feet
Clear cutting standards:
- Not allowed on highly erodible soils or where risk of sediment pollution is high
- Clear cut blocks, strips and patches are shaped and blended with the natural terrain
- The size of clear cut blocks, strips and patches are minimized
- Conducted between September 15 and May 15, when feasible.
- Clear cut areas are replanted to prevent erosion and to maintain the aesthetic quality of the area.
- The following distances from the Normal High Water Mark:
- Standards for grading and filling
Only land alterations accessory to a permitted or conditional use are allowed.?Consult local regulations on permit requirements for allowed land alteration activity.
Lower St. Croix Riverway
The Lower St Croix Riverway extends from Taylors Falls to the confluence with the Mississippi River. Land within the Lower St. Croix Riverway is defined by a legal description and by two districts within the legal boundary. Boundaries and districts may be mapped using the “Lower St. Croix National Scenic Riverway (LSCR)” dataset on MNGEO.
Lower St. Croix Riverway Program
- Bluff definitions
"Bluffline": a line along the top of a slope connecting the points at which the slope, proceeding away from the river or adjoining watershed channel, becomes less than 12 percent; For the complete definition see 6105.0354 Subp. 5.
- Bluff setback standards
Structure setbacks from a bluffline vary by district:
- Rural districts: ≥ 100 feet
- Urban districts: ≥ 40 feet
- Standards for vegetation management
Cutting of trees and shrubs is not allowed without a local permit:
- On slopes over 12%
- Within 40 feet of blufflines
- Within the following distances from the Ordinary High Water Level:
- Rural Districts: 200 feet
- Urban Districts: 100 feet
A local permit is only allowed for:
- Trees less than 6 inches in diameter at breast height
- Vegetation not screening structures from views from the river
- Activities that preserve essential character, quality, densite and continuous canopy
- Diseased trees, if removal is in public interest
Permits not needed for:
- The minimum necessary for activities under a building permit
- Maintenance of transportation and utility rights-of-way
- Standards for grading and filling
A local land alteration permit is needed for all soil disturbance activity except activity under a building permit. Consult local regulations on permit requirements for allowed land alteration activity.