WORKSHOP ITEM - Rebecca Haug, Water Resource Manager
Title
SOUTHERN BLAINE WETLAND SANCTUARY RESTORATION PLAN
Background
At the November 18, 2019 City Council meeting, Council authorized the execution of an agreement with Great River Greening to utilize grant dollars from the Outdoor Heritage Fund to restore the southern portion of the Blaine Wetland Sanctuary. Staff indicated that several plan options for the restoration work would be brought back to the council prior to any construction activity.
Throughout the planning process, several restoration options were considered and reviewed. All options include the preservation of native tree canopy species such as oak, American basswood, and black cherry trees. The state grant dollars are based on an acreage amount restored. The proposed options focused on allowing the maximum amount of grant dollars to be used.
Based on comments received by some of the residents during the October 24, 2019 open house and through the online comment period after the open house, additional buffer options have been created. These options include leaving a 50- or 100- foot buffer along treed property lines, along with a zero-foot buffer option. Additional requests made by residents include a 225-foot setback from the back of property lines along the northwest portion of 112th Circle NE.
The Natural Resource Conservation Board reviewed the options of leaving a zero foot, 50- or 100- foot buffer at their November 19, 2019 meeting.
The pros of leaving a 50-foot or 100-foot buffer is that it would alleviate some of the concerns of some of the residents. The concerns of the residents who are in favor of leaving a buffer is the loss of the view, privacy and home value. The cons of leaving a buffer are that a buffer will make it more difficult to conduct the prescribed burns, there will be loss of restoration benefits, and the project may lose some of the state grant dollars because of the reduction in acreage restored.
In the northern portion of the Blaine Wetland Sanctuary, trees were left in the islands to provide additional buffer. Unfortunately, there has been additional loss of these trees due to the loss of the canopy and disease. This has required city staff to remobilize and remove the trees to prevent future fire hazards during prescribed burns.
The NRCB also discussed what a managed buffer would look like. A managed buffer involves removing invasive and diseased trees as well as invasive vegetation, while healthy trees would remain. Currently, the areas which could create the potential buffer have a lot of buckthorn and invasive woody vegetation which should be removed. An unmanaged buffer where nothing is removed would be counter to the city’s responsibility to manage invasive species (see attached legal opinion from the city attorney).
An additional opportunity, found after the open house and presented to the NRCB, was to change the project as follows:
• The strip of land adjacent to Branch 3 and south of 117th Lane NE cul-de-sac has been removed from the project, as access is difficult.
• Several other areas have been identified where only buckthorn and invasive species removal will happen. The native species of oak, American basswood, and black cherry trees will remain.
• The above changes would allow for the resulting change in acreage to be used for the removal of the invasive species and buckthorn in the entire North Oaks West Park. This would reduce the future need for city resources to be used for invasive species management in the western portion of the park as that area was not previously identified for restoration.
Based on their discussion of buffers, the NRCB recommended the plan with a zero buffer along property lines. The rationale for their recommendation is outlined below:
1. Maximize the grant funding
2. Remain consistent with the original vision of the Blaine Wetland Sanctuary that was established in the 1980s when the city first acquired this open space, for Blaine residents to have an environmental education classroom and recreational area
3. Provide full restoration benefits
4. Manage invasive species. The invasive species that have been identified in this area include: common and glossy buckthorn, Amur maple, exotic honeysuckles, Russian olive, Siberian elm, Oriental bittersweet, Japanese barberry, black locust, and Siberian pea shrub
The restoration timeline is as follows:
• Work to begin after all requirements are fulfilled and weather permits.
• Great River Greening to select contractor after December 4, 2019.
• Heavy equipment work to be completed by March 1, 2020 unless weather conditions do not allow for the completion.
• All work to be completed by October 1, 2020 unless weather conditions do not allow for the completion.
The scope of work details include:
• Heavy equipment and material staging off of 109th Avenue NE contingent upon permit issuance from Anoka County Highway Department.
• Three additional staging areas are proposed inside the city’s property to reduce disturbance of the site
• Trees larger than 3 inches in diameter at breast height will have stumps ground.
• All material will be removed from the site and disposed of properly.
Updates will be provided throughout the process to neighboring property owners and any other residents who have signed up for notifications through the city’s website.
Recommendation
Approve the restoration plan for the southern portion of the Blaine Wetland Sanctuary with the following considerations.
• Staff and NRCB support approval of the acreage ‘swap’ of the strip of land adjacent to Branch 3 and south of 117th Lane NE cul-de-sac and the invasive species removal only areas in exchange for additional work in North Oaks West Park.
Determination of potential buffers around the perimeter of the project including:
• Buffer level of clearing:
o Approve a managed buffer - remove invasive species, buckthorn, dead and diseased trees.
o Approve an unmanaged buffer - no removals.
• Buffer widths:
o Approve NRCB recommendation to leave zero buffer.
o Leave a 50-foot buffer along all treed property lines.
o Leave a 100-foot buffer along all treed property lines.
• Buffer location:
o Apply buffer to only portions of the boundary where homes are within 150 feet to address lot characteristics.
o Apply buffer to entire project.