Agenda - Environmental Policy Board - 12/21/2015

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Environmental Policy Board (EPB) 5. 2. Meeting Date: 12/21/2015 By: Chris Anderson, Community Development Information Title: Consider Potential 2016 Landscape, Rain Garden, and Tree Planting Demonstration Projects in the Brookfield Subdivision Purpose/Background: During the review of one of the more recent additions in the Brookfield subdivision (west of CSAH 5, adjacent to Trott Brook), the City agreed to various commitments in exchange for fee title to a small, narrow lot that connected to Trott Brook. The primary commitment agreed to by the City was the construction of a trail from 170th Trail NW to the existing trail that runs parallel to the Brook. This 'mid block' trail would provide another, more convenient, access point to the Brook for a majority of the Brookfield neighborhood. The trail installation will have a landscape component, which leads to the purpose of this case. Observations/Alternatives: Staff is contemplating three (3) interrelated projects at this site. First, based on the proximity to Trott Brook and the wooded wetland fringe adjacent to the Brook, Staff believes that a landscape of wildflowers and native grasses is most appropriate. This will require much less maintenance over time than standard turfgrass and/or ornamental plantings would (no regular mowing or irrigation). Secondly, Staff is recommending the installation of a small rain garden in the boulevard area adjacent to this site. This happens to be at a low point in the road and thus, with a slight modification to the curb (installing a curb cut), a considerable amount of stormwater runoff can be diverted from the storm sewer system into this area for infiltration and recharge. The quantity of captured stormwater should be able to be calculated/modeled and thus, this could potentially provide useful information for future street reconstruction projects if a property owner were interested. The third component includes the planting of several oaks on the trail parcel and possibly one in the rain garden as well. This could serve as the City's Arbor Day activity for 2016, something that the Board has expressed a desire in revisiting now that the Environmental Expo and Tree Sale events are no longer programmed. These three complimentary projects would result in multiple benefits to the neighborhood and the environment. The trail connection creates a link to an existing trail from within the development, something that is lacking at the moment along this 3/4 mile long portion of the Trott Brook Trail. In addition, the projects would promote groundwater recharge and infiltration and likely would reduce sediment/nutrient loading of the stormwater pond south of 170th Trail NW. Both the prairie establishment and the rain garden would result in new pollinator habitat, which is being rapidly depleted across the state and nation. Both also generally promote sustainable landscapes and, once fully established, will reduce necessary maintenance inputs compared to more traditional landscapes (turfgrass). Finally, the tree planting event will reconnect the Board with the City's observance of Arbor Day, which addresses a desire stated by the Board earlier this year. Action: Provide general consensus to Staff to proceed with these three (3) interrelated project elements (native landscape, rain garden, and tree planting). Attachments