Consider a Request for a Variance to Impervious Coverage at 6151 140th Avenue NW (Project No. 25-118); Case of Zero Zone

The City has received a Land Use Application from Loucks, Inc., on behalf of Zero Zone (the "Applicant"), for a proposed building addition and parking lot expansion on the properties generally known as 6151 140th Avenue and 6030 Bunker Lake Boulevard (referred to collectively as the "Subject Property").  The Subject Property is within the Shoreland Overlay District.  The overlay district extends out 1,000 from the Ordinary High Watermark (OHW) of Magnesium Street Pond, also known as DNR ID# 2-116, which is designated as a General Development Lake.  The Shoreland Overlay District limits the amount of impervious surface coverage to no more than twenty-five percent (25%).  The existing improvements on the Subject Property equate to 39.9% impervious coverage and after the proposed addition, the impervious coverage would be 62.7%.  Thus, the Applicant is seeking a variance to the impervious surface coverage limitation.

Project Overview
The Applicant is proposing to construct a 57,875 square foot building addition and parking lot expansion on the Subject Property.  As part of this project, the Applicant is replatting the Subject Property into a single parcel so that the proposed addition will not straddle a property line.  The proposed addition will include increased space for production and manufacturing, along with an engineering lab, testing area, conference rooms, additional office space and a lunchroom.  The currently vacant parcel was acquired from the City in 2007 with the intention of accommodating future expansion.  The project will also increase available parking from 113 stalls to 269 stalls.

Variance
The Shoreland Overlay District restricts impervious coverage to no more than twenty-five percent (25%) of a property.  The Subject Property currently has 39.9% impervious coverage and with the proposed building addition and parking lot expansion, the impervious coverage will increase to 62.7%.  The Subject Property is over 100 feet away from Magnesium Street Pond, and is separated from the water body by Bunker Lake Boulevard, a four (4) lane county highway.  As part of the Site Plan, the Applicant is proposing two new stormwater basins to meet current stormwater requirements (including infiltration of the first 1" of rainfall).  Post-development runoff cannot exceed pre-development runoff rates and thus, the proposed improvements should not have any negative impact on the Magnesium Street Pond.

Staff did connect with the MN DNR on this project, prior to the Applicant submitting this Land Use Application.  The DNR Area Hydrologist noted that their greatest concern with impervious coverage is within the Shore Impact Zone (SIZ), which is calculated at fifty percent (50%) of the minimum setback from the OHW.  For General Development Lakes, which Magnesium Street Pond is classified as, the setback from the OHW is fifty (50) feet, making the SIZ twenty-five (25) feet from the OHW.  The proposed improvements are far outside this area.  Additionally, per the Lower Rum River Watershed Management Organization (LRRWMO) standards, the first one inch (1") of rainfall must be infiltrated on site.  This standard did not exist when the Subject Property originally developed.  Thus, this will provide enhanced stormwater management compared to the original development of the Subject Property.

Staff had correspondence with the MN DNR prior to this application being officially submitted to the City.  At that time, the DNR noted that they would encourage the use of appropriate stormwater infiltration practices, such as riparian vegetation, permeable pavement, bioretention, etc.  The Applicant is proposing to utilize riparian seed mixes for the infiltration basins ('Wet Ditch' and 'Emergent Wetland' seed mixes). Additionally, the majority of the tree species are native to Minnesota, and the project must comply with both the City's and the LRRWMO's stormwater management standards.  Staff has forwarded the Site Plan and Landscape Plan to the DNR for official comment.

Tree Inventory and Preservation Plan
A tree inventory and preservation plan is required, but has not yet been submitted.  However, if not for the need for a variance to the impervious surfacing coverage, this project would have been reviewed as an Administrative Site Plan.  The same information that is required for a standard Site Plan is required for an Administrative Site Plan.  The difference is that with an Administrative Site Plan, the civil plans (grading, utilities, landscaping, etc.) are reviewed as part of the Building Permit submittal.  Thus, a tree inventory and preservation plan is still required, but will be reviewed when the Applicant applies for a building permit.

Landscape Plan
A Landscape Plan has been submitted.  The required landscaping is based on the Canopy Cover Formula.  As proposed, the Landscape Plan does meet the minimum square footage of canopy cover required.  As already noted, the majority of the tree species are native.  Ground cover will consist of turf sod and a couple variations of riparian seed mixes (for the two infiltration basins).  There are some minor corrections necessary, as noted on the various plan sheets, but overall, the proposed landscaping is acceptable.

All costs associated with this request are the Applicant's responsibility.

Staff recommends approval of the variance for impervious surface coverage and the Landscape Plan, contingent upon compliance with the review comments. 

Motion to recommend approval of Resolution #25-215 granting a variance to impervious surface coverage within the Shoreland Overlay District for Zero Zone.