Consider Request for a Variance to Utilize an Alternative Technique for Collecting the Tree Inventory Data for Serenity at Rivers Edge (Project 26-101)

The City has received a Land Use Application from Rivers Edge Development LLC (the "Applicant") for a variance to deviate from the standard tree inventory methodology for the plat known as Serenity at Rivers Edge.  The project is located on the south side of Riverdale Drive, between Dolomite Street and Sunfish Lake Boulevard (the "Subject Property").  The Applicant is proposing to use a Fixed Radius Plot methodology, rather than tagging each individual significant tree, due to existing site conditions.

Development Summary
The Applicant is proposing to subdivide the Subject Property into two (2) single family residential lots along with a large outlot.  The intention is to develop the entirety of the Subject Property into single-family residential lots. However, the Applicant cannot currently meet the density requirements (2.25–4 units per acre), without essentially clear-cutting the existing tree cover on the Subject Property.  But, the Subject Property abuts the Mississippi River, which means it is also located within the Mississippi River Corridor Critical Area (MRCCA).  This overlay district includes additional regulations, specifically addressing vegetation management and land disturbance, amongst other things.  The Applicant has stated a desire to limit the overall impact on the Subject Property and has proposed to 'custom' develop each lot to minimize impacts on existing natural resources.  As part of the upcoming Comprehensive Plan Update process, Staff will be proposing a 'River District', applicable to both the Scenic River Protection Overlay District and the MRCCA, which would permit a lower density.  The purpose of a lesser density would be to align more with the intent of both overlay districts, which is to minimize disturbance of existing natural resources.

Proposed Tree Inventory Methodology
There is significant tree cover on the Subject Property, primarily consisting of eastern red cedar, with other species, both coniferous and deciduous, sprinkled throughout the site.  The tree cover is very dense, and considering that the vast majority of trees are evergreens (eastern red cedar) with branching down to the ground, it would be very challenging, time-consuming, and costly to complete a standard tree inventory (locating and tagging each significant tree).  Furthermore, many of the lowest limbs are dead, due to a lack of sunlight reaching them, posing more of a safety risk for the individual(s) that would be conducting the inventory (these branches can be sharp). Thus, the Applicant is proposing to map the precise boundaries of the wooded areas and then utilize Fixed Radius Plots (FRP) to collect data and then extrapolate that out to the entire Subject Property. 

The Subject Property is nearly a monoculture of eastern red cedars that appear to all be roughly the same height and are in similar growing conditions and soil.  Thus, the FRP method would be an acceptable alternative method.  This is the same methodology that was used for the tree inventory and preservation plan for a different development in the northern part of the City (this project was granted a variance to utilize FRP to complete the tree inventory and develop their tree preservation plan).  Within the Subject Property, the Applicant would establish 1/10 acre plots and all trees within these plots would be inventoried.  Once completed, the data can be extrapolated out to the entire site to provide a relative basal area, relative species abundance, and relative health condition, which can then be used to formulate the tree preservation plan.

The Subject Property is within the Mississippi River Corridor Critical Area (MRCCA) Overlay District, which has additional vegetation management standards above and beyond the basic tree inventory and preservation plan.  For example, at the time of building permit application submittal, the builder will also need to apply for a Vegetation Permit, which will specify exactly which significant trees will need to be removed to facilitate the installation of the home, driveway, and utility connections.  The Tree Inventory will give a high-level overview of existing tree cover on the Subject Property, while the Vegetation Permit will focus on more specific tree removals on a specific lot. 

When contemplating a variance, a three (3) factor test must be applied to determine whether 'practical difficulties' exist.  The three (3) factor test includes:

1. Reasonableness — The proposal is to utilize an alternative inventorying technique, not to eliminate the need to do an inventory.  The vast majority of the trees on site are a single species (eastern red cedar) that share similar size characteristics and growing conditions.  Therefore, the FRP technique should provide a fairly accurate accounting of existing trees and thus, the proposal is reasonable. 
2. Uniqueness — The denseness of the eastern red cedars, including the fact that their branching extends down to the ground, has resulted in a lot of dead branches (due to a lack of sunlight reaching them) that creates a safety concern for anyone conducting a tree inventory and presents a significant physical obstacle to tagging each individual significant tree. 
3. Essential Character — This alternative sampling technique will not have any bearing on the essential character of the surrounding area.  There will be persons on the ground collecting tree data (whether using the FRP technique or conducting a standard inventory).  This is just data gathering and will not have any direct bearing on the layout of the proposed development. 

The Applicant is responsible for all costs associated with this request.

Staff recommends approving the variance request.  Additionally, Staff is also recommending a minor amendment to the tree preservation section of City Code that would allow alternative methods of collecting data for a tree inventory without needing to seek a variance.  If there is support from the Environmental Policy Board, Staff would prepare an Ordinance Amendment for consideration at a future meeting.

Motion to recommend approval of a variance to use an alternative methodology to complete a tree inventory on the Subject Property.