City of Shell Lake

Shoreline Buffer Mitigation Standards

Definition:

A shoreline buffer is a zone of native vegetation that extends from the ordinary high water mark inland. The width of the shoreline buffer, otherwise referred to as the shoreline vegetation protection area, is to a line 40 feet less than the required building setback from the ordinary high water mark (OHWM), 35 feet inland for class 1 waters, 60 feet inland for class 3 waters and 35 feet inland for all rivers. As of October 20, 2004 according to Shell Lake Zoning Ordinance, the disturbance of the shoreline vegetation protection area, which includes the removal of trees shrubs, groundcover, and land disturbing activities, is prohibited. The purpose of the shoreline vegetation protection area is to provide wildlife habitat, prevent erosion, purify runoff water, and provide an aesthetically pleasing shoreline.

Required shoreline buffer restorations:

A shoreline buffer must be restored when:

1. A nonconforming principal structure, of at least 750 square feet of enclosed, habitable, living space, is improved or expanded, other than ordinary maintenance and repair.

2. A conforming principal structure is expanded 50% or more in enclosed floor area, or when a new principal structure is built.

3. A shoreland vegetation protection area violation occurs.

Required shoreline buffer restorations shall comply with the standards contained in the Shoreland Vegetation Protection Zone cited below. The vegetation protection zone shall extend from the ordinary high water mark to a line 35 feet inland in the case of expansion of nonconforming or conforming principal structures. In the event of a shoreline vegetation protection area violation for construction after October 20, 2004 the buffer shall be restored to the current standards of class 1 and 3 waters in effect on the date of the violation.

The shoreline vegetation protection zone:

The shoreline vegetation protection area must consist of a mix of native trees, shrubs, and ground cover. There are two zones to a shoreline vegetation protection area.

The shoreline buffer zone

A no disturbance policy is enforced within the shoreline vegetation protection zone (once the buffer is established). Within this area the removal trees, shrubs, and groundcover is prohibited with the exception of noxious vegetation.

The viewing and access corridor

One viewing and access corridor is permitted per 100 feet of water frontage per lot. It shall be no more than 30 feet wide in the dimension paralleling the shore and shall be set back at least ten (10) feet from the side lot line. In the case of a lot less than 100 feet in width, the viewing and access corridor shall be reduced proportionally. Within the viewing and access corridor selective removal of vegetation is permitted. Sufficient vegetation shall be retained to screen development from view and provide a filtered view of the water. Clearcutting, grading, or other land disturbing activities are prohibited (except in the viewing corridor). Walkways, stairs, and paths must be located in the viewing and access corridor unless such location is not feasible due to steep slopes, wet soils, or similar conditions. Piers and lifts must be placed in water immediately adjacent to the viewing corridor.

Buffer Dimensions:

Length

The shoreline buffer shall extend the entire length of the lot along the shoreline except for the viewing corridor.

Width

In the case of required restorations for conforming and nonconforming principal structures, the buffer shall extend 35 feet inland from the ordinary high water mark on Class 1 waters and 60 feet on Class 3 waters, or to within 25 feet of the structure. All other buffers shall extend inland from the ordinary high water mark to a line that is 25 feet less than the required building setback.

Minimum re-vegetation standards:

The buffer shall consist of three (3) layers of vegetation; a tree canopy, a shrub understory, and a groundcover layer. The entire buffer zone must be vegetated to the planting standards described in Table 1; no bare soil will be permitted.

Recovery methods:

1. Natural recovery

Native vegetation will recover naturally provided the site is protected from disturbance and an adequate seed base or source remains. Natural recovery will be encouraged when appropriate. Natural recovery is the least expensive and most natural form of recovery. It may take slightly longer than a planted recovery but will most closely mimic the surrounding vegetation.

2. Accelerated (planted) recovery

Areas not suited to natural recovery will require plantings to establish native vegetation and must be planted. Areas such as lawns or eroded sites with no seed source will require plantings. Dense turf grass growths that have been maintained for several years will need to be removed and native plantings installed. Planted buffers must meet the required plant densities based on square footage of buffer area and the type of buffer (Table 1). Planting credits will be allowed for the viewing corridor, areas of existing native vegetation, and areas suited for natural recovery.

Two buffer types with different standards, a woodland buffer, and a prairie buffer shall be the required restorations (Table 1). Wetland buffers will also be permitted where appropriate. However due to a wetland’s ability to recover naturally no standards will be required.

Table 1: Guidelines for Shoreline Buffer Planting Standards

Woodland Buffer

Prairie Buffer

Layer

Minimum number of species

Density per 100ft²

Minimum number of species

Density per

100 ft²

Area Credits

Tree Canopy

0.2

Existing Tree Canopy

Wet Edge

Viewing corridor

Shrub Understory

1.5

(may be clumped)

0.5

(may be clumped)

Existing Shrub Understory

Wet Edge

Viewing corridor

Groundcover

plant plugs

Existing well vegetated native groundcover

Groundcover

seeding

Varies

Existing well vegetated native groundcover

Species must be selected from a list of plants native to Washburn County and approved for shoreline buffers by the Washburn County Planning, Land and Resource Management Department. Substitutions must be approved by the Washburn County Planning Land and Resource Management Department. All plants may be transplanted from areas outside of the buffer zone.

Densities are based on the total area of the required buffer. Area credits calculated are subtracted from the total required density on an equal square footage of coverage basis. Plantings are required in the uncredited areas.

Trees must be at least 2 years old and greater than 1 foot tall to qualify as a credit or planting

At least one native grass must cover at least 30% of the required groundcover area in prairie buffers.

Groundcover plant plugs must be mulched after planting to qualify as a planted credit.

Planting Dates:

Final plantings must be installed within the specified planting dates (Table 2). Bare ground must be planted and stabilized from erosion immediately.

Table 2: Guidelines for Planting dates for shoreline buffer restoration layers.

Layer

Planting Date(s)

Dormant/Late Summer Seeding Date(s)

Tree Canopy

April 15 - November 15

None

Shrub Understory

April 15 - November 15

None

Groundcover Plant Plugs

May 15 - September 15

None

Ground Cover Seeding

Warm Season Grasses

Cool Season Grasses

Thaw - July 15

May 1 - June 15

October 8 - Snow Cover

July 15 - August 10

Erosion Control Requirements:

All exposed soil must be mulched. A temporary seeding or cover crop must be used on sites where permanent groundcover will not be established until the following year. A site will not be allowed to remain as bare ground with the intention of planting the following growing season. A temporary or cover crop seeding is required with the permanent planting or seeding on all slopes 12% or greater. Mulch and netting or erosion control mats are required on all sites with slopes of 20% or greater. Required erosion control best management practices shall be in place prior to all land disturbing activities. Slopes shall be calculated as the total change in elevation over a 50 foot horizontal distance.

Runoff Control:

Runoff from impervious surfaces, such as roof tops and driveways, shall be directed to maximize infiltration. Runoff water shall be maintained in sheet flow (not channelized flow) to the maximum extent practicable.

Shoreline Buffer Plan Requirements:

A Shoreland Re-vegetation Plan shall be completed for all required shoreland mitigation or preservations. A similar plan and agreement shall be completed in the event buffer zone violation. Sample plans and agreements are available from the Washburn County Planning, Land and Resource Management Department. Plans must be approved by the Washburn County Planning, Land and Resource Management Department. Technical assistance is available through the Washburn County Planning, Land and Resource Management Department for Shoreland Re-vegetation Plans.

Plans Must Include:

Name and Address of property owner

Property Address and Legal Description to 1/4, 1/4

Extent of the Shoreline buffer

Scale (1 inch = 10 feet recommended)

North Arrow

Ordinary High Water Mark (OHWM) Location

Location of all Structures in the Shoreline Buffer Zone

Viewing and Access Corridor

Boundary of the Shoreline Buffer Zone

Existing Trees, Shrubs, and Native Groundcover

Areas to be Planted with Trees, Shrubs, and Groundcovers

A Plant Species List; indicate if you are requesting substitutions from the prepared list

Erosion Control Practices (to be installed prior to and during buffer establishment)

Water Diversions and Channelized Flow Areas

Plant Materials:

Plant species must be selected from a list of plants that are native to Washburn County. The list is available at the Washburn County Planning, Land and Resource Management Department. Additional species must be proposed in writing to the Washburn County Planning, Land and Resource Management Department, which may approve or deny the requested addition. Substitutions to the list will be allowed in the event of lack of plant stock or seed availability on a case by case basis. Planting instructions for trees, shrubs, and groundcovers, are available from the Washburn County Planning, Land and Resource Management Department.

Buffer Maintenance:

The intent of the vegetation protection zone is to return to, and remain in, a natural vegetative state. The area requires minimal if any maintenance. There is no need to mow, rake, clean up fallen branches, or fertilize.

Some initial maintenance will be needed to establish a shoreline buffer for planted recoveries. Weeding around native trees, shrubs, and groundcovers will be needed the first year or two, to allow the native plants to establish themselves and compete with invasive weeds. Buffers will ultimately be maintained according to ordinance requirements.

Mowing of groundcover in prairie areas will be allowed once every 3 to 5 years with notification of and approval by the Washburn County Planning, Land and Resource Management Department. Mowing may be performed no earlier than July 15 to minimize adverse impacts to wildlife.

Fertilizer use is discouraged. Native plants have evolved to grow without assistance. Any fertilizer used to establish the shoreline buffer must not contain phosphorus. Herbicide use is discouraged except where authorized to control noxious vegetation.

Vehicle use is prohibited in the vegetation protection area except for limited use in the viewing and access corridor.

Docks, piers, swimming rafts, boats, etc, must be stored in the viewing and access corridor if possible.

Table of Dimensional Standards
Standard	Water class
	Class 1 Shell Lake	Class 3 Round, Little Ripley & Chain Lakes & all rivers & streams
Min. lot area	30,000 sq. ft.	3 acres
Min. lot width	150 ft.	300 ft.
Min. side yard	10 ft. one side & 25 ft. total both sides for principal structure. 3 ft. for accessory structures
Min. front/road yard	25 ft.
Min. shoreline setback	75 ft.	100 ft. on lakes/75 ft. on rivers & streams
Shoreline vegetation protection area	No disturbance within 35 ft. of shoreline with specified exceptions. Mowing of pre-established lawns is permitted unless mitigation is required.	No disturbance within 60 ft. of shoreline on lakes & 35 ft. on rivers & streams with specified exceptions. Mowing of pre-established lawns is permitted unless mitigation is required.
Min. wetland setback	25 ft.
Min. drainageway setback	10 ft.