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HomeMy WebLinkAboutMn Wetland Conserv Act Tech. Eval.findings Minnesota Wetland Conservation Act Technical Evaluation Panel Findings Report Date(s)of Site 9/29/2014 LGU: Minnehaha Creek Watershed District Visit/Meeting: County: Hennepin LGU Contact: Courtney Hall Project Name: Nelson Restoration Phone#: 952-473-2855 Location of Project: 520 Tonkawa Rd,Orono Email chall@minnehahacreek.ora (attach map If possible) Address: TEP ATTENDEES: OTHER ATTENDEES: OTHER ATTENDEES: LGU:Courtney Hall Applicant's Representative: Doug Mensing,AES,Inc. SWCD: BWSR:Ben Meyer DNR: PROJECT DESCRIPTION AND PURPOSE OF MEETING: See"Introduction"In attached Technical Memo TYPE OF MEETING:Check oiloppllcoble ❑ Office ® On-Site ❑ 6one Conference ❑ E-mail ❑ Other: TEP FINDINGS AND RECOMMENDATIONS'; Members of the Technical Evaluation Panel(Ben Meyer from BWSR and Courtney Hall from MCWD)met on site to dicuss the technical merits of the restoration and to assess the public value of the wetland.The TEP said that It order for the project to qualify for No-Loss,the project would have to result in an Increase of wetland function.The TEP discussed the technical merits,public value,and assurances of the project with the applicant and summarized the findings in the attached technical memo. The TEP recommended approving the proposed restoration project as a No-Loss as the activities do not fulfill the criteria of the definition of an"impact"as defined In the WCA and will result in an increase in function and value of the wetland. SIGNATURES SWCD Representative Date BWSR Represen a v Date Do not concur ❑ Do not concur ❑ 10/6/2014 . L Representative Date DNR Representative Date Do not concur ❑ Do not concur ❑ 1 TEP Findings should be a meaningful concise summary detailing.the project conditions, technical data, and what rules apply. The TEP recommendation should be clear,based on rule and best professional judgement. Rev.12117n013 MINNEHAHA CREEK WATERSHED DISTRICT QUALITY OF WATER QUALITY OF LIFE Memo To: Ben Meyer, BWSR Stacey Lijewski, Hennepin County From: Courtney Hall, MCWD CC: Date: September 23,2014 Re: Wetland Conservation Act No-Loss Application W14-37 Nelson Restoration I. Introduction Dr.Glen Nelson has applied for a No-Loss determination for the proposed restoration of a 2.98 acre wetland in the City of Orono(PIDs 0511723320005 and 0511723330018).The wetland is a Shallow Marsh that is dominated by hybrid cattail,purple loosestrife,and reed canary grass.The wetland has low vegetative diversity and low wildlife habitat value. Dr. Nelson has hired Applied Ecological Services, Inc to design and implement a wetland restoration at the above-mentioned site. Dr. Nelson is not required to restore the wetland for replacement credits nor is he looking to sell wetland banking credits. He is interested in improving the biological diversity of the wetland and surrounding upland.This is a privately funded,good-will effort to improve the quality of the wetland. The Minnehaha Creek Watershed District is the local government unit that administers the Wetland Conservation Act in the City of Orono at this site and is responsible for making decisions on applications.The MCWD has called upon the TEP to analyze the technical merits of the restoration,assess public value of the wetland,and interpret the intent of the Wetland Conservation Act. II. Background Based upon historical aerial review(attached),the wetland appears to have been drier with the northern portion of the wetland likely supporting hay production.The southern portion of the wetland was wooded, and was likely made up of lowland forest or wet forest communities.Currently,there are still small pockets of wet meadow species,which also suggests that this wetland was historically a wet meadow community.These wetland communities that existed historically were sensitive to stormwater input and urban development. The historic hydrology of the wetland has been altered by construction of Tonkawa Road, nearby urban development,and installation of culverts.The road acts as a berm and prevents water from dissipating from the wetland,which has resulted in a wetland that is inundated for longer periods of time. Prolonged periods of i Inundation would have resulted in a conversion of wetland communities adapted to saturated soils(i.e.wet meadow communities and lowland wet forest communities)to the shallow marsh community that exists today.The culverts probably have had less of an impact over time.However,they are impounded and reduce flow out of the wetland and result in fluctuating hydroperiods of inundation that stress native wetland plant communities. III. Restoration Restoration In the WCA(8420.011 Subp 62)refers to the reestablishment of historic wetlands or wetlands that are degraded.The subject wetland has been degraded due to disturbance of its natural condition by human activities.This has resulted in low to moderate wetland functions and values under the existing condition.The wetland has moderate water quality and storm water retention functionality.However,it is nearly a monotypic stand of hybrid cattail and supports little wildlife. To truly restore the historic hydrology of the wetland that would have supported saturated soils and wet meadow communities,the culverts under Tonkawa Road would have to be expanded or lowered.Expanding or lowering the culverts would draw down water levels to promote saturated soils and the establishment of wetland vegetation communities adapted to these soil conditions.Drawing down water would be prohibited by the WCA.It would be considered an impact because it is an activity that drains a wetland and would likely reduce the overall size of the wetland.The applicant has proposed an alternative restoration technique that still achieves hydrologic and vegetative restoration,but will not result in loss of wetland quantity. The applicant has proposed restoring the historic wet meadow community by excavating approximately 2,588 cubic years of wetland soil from a 0.5 acre portion of the wetland and thin-spreading the material over lower portions of the wetland to a maximum elevation of 964.5 feet in order to maintain wetland conditions.A wet meadow seed mix will be broadcast over the thin-spread area to restore a wet meadow community.Plugs of marsh plant species will be installed in the excavated area.This will improve biodiversity of the wetland by creating two additional wetland community types.In addition to a lowland wetland forest community that exists now and will remain,the wetland will have a wet meadow component that will have greater floristic diversity and will attract birds and pollinators,as well as a deep marsh habitat that will promote amphibian and waterfowl habitat.The restoration will also Increase beta diversity at the landscape level by creating a diverse wet meadow wetland. High quality wet meadow wetlands are lacking within the Minnehaha Creek Watershed District because they have been degraded and are dominated by invasive species.The TEP recommended including a fallen log in the proposed deep marsh portion of the wetland to provide an area for heron and turtle perching,and to have an area for tadpoles to hide.The applicant agreed to include this. Aside from Improvements to the wetland itself,the proposed project includes restoration of the wetland buffer plant community through removal of invasive species and planting of native forest species.The proposal also includes improvements to water quality.The applicant plans to install two rain gardens that will treat an area of approximately 1.42 acres of runoff prior to entering the wetland.Therefore,the proposed restoration will increase the public value(MN Rules 8420.0522 Subpart 1)of the wetland by improving water quality,native plant habitat,and wildlife habitat.It will also promote advancement in wetland restoration science as an innovative and replicable wetland restoration technique. IV. Restoration Technique The success of the restoration depends on the ability to limit the growth of cattail in the wetland.Other cattail management techniques were researched and are outlined below.However,most are ineffective if not paired with the direct manipulation of water levels.The thin spreading of material is a technique that will manage cattails as well as provide an area for native wetland plant re-establishment. Cut and Flood The most effective cattail management technique is to cut the cattail stems and leaves and subsequently flood the wetland area for a prolonged period of time.This method works well because it precludes germination by reducing light to cattail seeds and it disrupts the function of the aerenchyma.Aerenchymha are channels in plant tissue that allow oxygen to be transported to the rhizomes,which is an essential adaptation In plants for survival in wetlands.Cutting the cattails and raising water levels above the cut stems and leaves drowns the cattails.This greatly reduces cattail density and prevents future germination.This technique was explored by the applicant.It would require flooding the basin and roadway embankment for an extended period of time. Hennepin County Transportation Department advises against raising water levels In the wetland.If cut leaves and stems are not submerged,however,this method becomes ineffective. Herbicide Another cattail management method is to apply herbicide.After herbicide application,the resultant exposed soil can be seeded with a native wetland seed mix.Where seeding wetland plants in exposed soil is a good technique for establishing native vegetation,it has not been shown that seeding alone will out-compete invading cattails.This may be because cattails have a competitive advantage when there is an abundance of cattail leaf litter.Therefore,if the cattail seedbed and litter has not been removed,it is likely that the area will remain dominated by cattails.Removing the cattail seedbed would require excavation. Proposed Thin-Spread Because manipulating the hydrology of the wetland Is not feasible and herbicide treatments alone will likely fail in the long-term,the applicant has proposed an innovative cattail management technique.This method involves the thin-spreading of excavated wetland soil over an area that is currently dominated by cattails. Existing cattail propagules will be removed from the excavated soil prior to spreading the material over an area of herbicide-killed and burned cattails.Thin-spreading this soil will bury the existing cattail seedbank and will reduce germination by eliminating light availability to cattail seeds.It will also create a large,level planting area to seed with a native wetland mix.When native wetland plants are allowed to establish without competition from invaders,they are good at outcompeting invasive species in the long term.Therefore,it is likely that this technique will result in long-term delivery of public benefits. V. Assurances To assure that the project is achieving intended restoration goals and improved public value,the applicant has outlined projected outcomes and proposed monitoring,maintenance and reporting.The applicant has collected two rounds of baseline wildlife data for birds,amphibians,and Odonata(dragonflies and damselflies).The applicant will be collecting another round of data this fall.Post-construction data will also be collected.These data have been compiled in order to document the response of birds,amphibians,and other biotic quality indicators to the restoration.This type of data collection will help to inform and educate wetland professionals on expectations for wildlife response following restoration. In addition to wildlife data,the applicant has committed to three years of post-construction wetland monitoring and reporting,and will follow the MN Board of Water and Soil Resources Replacement Wetland Annual Monitoring Report format.The applicant will perform short term management activities to meet performance standards and has set high performance standards for the restoration activities,which include less than 20%cover of invasive species and greater than 80%vegetation cover in the restored wet meadow community.The applicant will be required to submit the monitoring reports to the MCWD on or before January 11 of each year for 3 years. The applicant will be required by the Minnehaha Creek Watershed District to have financial assurance for the proposed wetland restoration.The District will have the option to draw upon this if warranted to do so.The financial assurance will be released to the applicant only when performance standards have been met at the end of the final year of monitoring. VI. Summary of Benefits The purpose of the Wetland Conservation Act is to achieve no net loss in Minnesota's wetlands and to increase the quantity,quality,and biological diversity of diminished wetlands by restoring or enhancing them. The proposed project will result in a more diverse,higher quality wetland that is composed of three wetland plant communities.The project will improve and create habitat for birds,amphibians,and pollinators (attachment Memorandum 9/15/2014).The proposed restoration technique is based upon information advanced from other successful cattail management studies and is an opportunity to inform future wetland restoration. After reviewing meeting on site with the applicant to review the benefits of the project,the restoration activities do not meet the definition of impact(MN Rules 8420.0111 subp 33).According to the rule,in order for an activity to constitute an "impact",the proposed activity must fulfill both criteria described in the definition:a)it must be draining or filling(or excavating in a type 3,4,or 5)and b)the draining,filling or excavating must result in a loss in the quantity,quality,or biological diversity of the wetland.The proposed activities,therefore,would not be an"impact"as they do not result in the loss of quantity of wetland and are restoration techniques used to increase the quality and biodiversity of the wetland.The proposed restoration will result in a functional improvement of the wetland. VII. Recommendation The Minnehaha Creek Watershed District is the local government unit that administers the Wetland Conservation Act and is responsible for making decisions on applications.The MCWD has called upon the TEP to analyze the technical merits of the restoration and assess public value of the wetland.The District and the Technical Evaluation Panel recognize that the restoration project will provide multiple benefits.The proposed project will restore a degraded 2.98-acre wetland,improve water quality entering the wetland,and restore upland plant communities in the buffer adjacent to the wetland.The applicant has committed to financial assurances and has outlined post-construction monitoring and maintenance. The TEP is recommending approval of the proposed restoration as applied for under"No-Loss"as the activity does not fulfill the two criteria of the definition of an"impact"as defined in the WCA and will result in an increase in function and value of the wetland. '/vA, 2v Courtney Hall, MC D Wetland Specialist Date