1. Design to reduce flood risk. Design should build upon best available flood risk data (at a minimum MSD, PDA, and concurrent Regional Watershed Management, Flood Mitigation & Green Infrastructure Plan). a) Conduct site surveys at locations identified in coordination with PDA. b) Runoff volume reduction capabilities of each Project shall be calculated by project design engineer. A reduction of runoff volume and total drainage area managed must be demonstrated and supported with calculations, site assessment, engineering and modeling, in coordination with regulatory agencies (MSD). Note: All public or private sewerage and drainage works proposed to be constructed, altered or reconstructed within MSD boundaries requires review and approval by MSD. This includes any altering of any storm drainage channel, site drainage or flood plain. c) Designed to be constructed to pass or exceed MSD Rules & Regulations (2018 or latest version) for private development. All projects must be designed and constructed in accordance with the following documents. (1) MSD’s Rules, Regulations and Engineering Design Requirements for Sanitary Sewage and Stormwater Drainage Facilities (2) Standard Construction Specifications for Sewers and Drainage Facilities (3) Design in alignment with location of MSD Existing Municipal storm drains, as well as future stormwater infrastructure upgrades planned by MSD, St. Louis City Forestry Division, MSD Project Clear Large Scale Rainscaping Programs, Forest ReLeaf, and other projects for which flood risk infrastructure projections are available. d) Preference shall be given to projects that can manage at least 1.14 inches of stormwater rainfall from the contributing drainage area. A reduction of runoff volume must be demonstrated and supported with calculations. Reference the Maximum Extent Practicable (MEP) spreadsheet and calculation tool available at the MSD website; https://msdprojectclear. org/what-we-do/stormwater- management/ bmp-toolbox/ calculation- and-report-preparation- tools/ 2. Design to maximize Social and Ecological Co-Benefits. a) Designs should align with and build on recent and current planning efforts related to resilience, Neighborhood Planning, Greenway development, and park connectivity. b) Projects should include recreational and aesthetic benefits to current residents and support new development. For instance food forests, shade trees, benches, seasonal interest, exercise, sports, and play equipment. c) Projects should make maximum use of public resources. Projects should be designed in close collaboration with related city departments and agencies (Streets, Forestry) to deliver long lasting functionality, connectivity, simple maintenance, as well as beauty. Coordination with city departments and utilities should be prioritized to ensure new infrastructure installation is aligned across organizations. Projects should be a functional asset as well as a community amenity which increases urban greening, neighborhood aesthetics, and new housing development. 3. Develop a Planting Plan that sets up a minimized maintenance regime. a) When incorporating a planting plan, develop a planting design that utilizes native locally sourced plants in close collaboration with the St. Louis Forestry Department. Plant selection should emphasize water absorption, drought tolerance, passive production of food (food forest), biodiversity, all season interest, and appropriateness in neighborhood context. The planting layout should emphasize ease of maintenance - consider rows of similar plants to stream line annual pruning, large trees in the center of lots rather than edges to allow for branches to safely shed and protect the drip line from excessive mowing. Safety and visibility should be a forefront concern especially along sidewalks and bikeways. Tall emergent vegetation along edges should be avoided to maintain clear sightlines, ensure safety, and to minimize maintenance cost for clearing viewing corridors. Lower emergent vegetation optimal. Consider a gradational approach to planting based on time and duration of water inundation.
