Neighborhood Infrastructures Blue Green Infrastructure Blue green infrastructure refers to the components of the neighborhood fabric that connect habitat, parks and open space while managing stormwater. Historically, construction of grey infrastructure, such as sewer systems and enclosed rivers and streams, has been how Parkview Gardens has the neighborhood, was buried and now expensive gray infrastructure is at the headwaters of the River Des Peres drainage basin, the single largest drainage basin in the St. Louis metro area. It is served by an aging combinedsewer system in which stormwater is combined with sanitary waste. Parkview Gardens is 60% impervious surface and, with compacted urban soil conditions, much of the other 40% is less than 100% absorbent. Because of this level of imperviousness, these gray infrastructure systems are easily overwhelmed pollution, and poor water quality in the watershed. The various strategies for blue and green infrastructure aim to reduce the amount of impervious surface in the neighborhood, help mitigate the negative environmental effects of stormwater runoff, decrease the maintenance and need for replacement of gray infrastructure, and improve the quality of the public realm. Over the long term, managing stormwater at the surface level with blue green infrastructure and public realm improvements will improve quality of life and environmental equity, and be more cost effective and environmentally friendly than maintaining existing aging infrastructure systems. 5.0 Neighborhood Sustainable Development Plan: Blue Green Infrastructure 199
Overview: Blue Green Infrastructure Urban Forest As part of the stormwater system, trees absorb the largest amount of water in the neighborhood particularly because lawns and grasses are compacted and water runs off those surfaces. Maintaining a healthy number of mature and growing trees is key to how much water can be absorbed. Trees also enhance neighborhood, biodiversity, habitat, and reduce urban heat island effect. Sample rain gardens in sidewalk Parks, Public Space, & Community Gardens Planted areas in parks, public spaces, and community gardens can be can be accomplished using native landscaping, trees, water features or fountains, rain gardens or bioswales, and permeable surfaces. These public spaces are essential for stormwater management and are a unique asset for Parkview Gardens. Permeable Pavement & Green Alleys Streets, alleys, and sidewalks can be redesigned using various permeable pavement options to reduce the negative environmental and economic effects of stormwater runoff. The redesigned right-of-ways will give new vibrancy and identity to the streets while preserving the human scale and positive qualities that make Parkview Gardens a walkable and livable neighborhood. Green Medians & Native Plants Parkview Gardens historic planning created planted street medians with turf grass and trees. The Plan recognizes these for creating unique neighborhood street character, but they have the potential to absorb and retain more stormwater with trees, native plants, rain gardens, or bioswales and should also be designed so residents can continue to meet, walk, rest or walk dogs. Native plants requires less water, less maintenance, contribute to water absorption and soil remediation, and will also help Parkview Gardens reach the goals for stormwater runoff mitigation. Green Roofs Green roofs increase the amount of permeable surface and absorb stormwater. Increasing permeable surface reduces the amount of tax property owners pay to MSD and helps overall neighborhood stormwater management. Other energy use and urban heat island effect, improving public health, and increasing space for rooftop gardening or patios. Stormwater Collection On-site stormwater collection systems such as rain barrels and underground cisterns decrease stormwater runoff and collect water to be used for non- washing, water chilling systems, etc. They reduce the impact on gray infrastructure, reducing maintenance and replacement costs; reduce use of for fresh water. 200 Draft Parkview Gardens Neighborhood Sustainable Development Plan
Blue Green Infrastructure Urban Forest Parks, Public Space, & Community Gardens Permeable Pavement & Green Alleys Green Medians & Native Plants Green Roofs Stormwater Collection 5.0 Neighborhood Sustainable Development Plan: Blue Green Infrastructure 201
Urban Forest Existing tree canopy (Figure 28.2) Figure 28.1 Existing tree canopy coverage area (Figure 28.3) Proposed tree canopy (Figure 28.4) Proposed tree canopy coverage area (Figure 28.5) Analysis of Existing Conditions The urban forest in Parkview Gardens is 75% healthy and 20% mature, and substantially more water than young trees. The existing tree canopy covers 17% of the neighborhood (Figure 28.2, 28.3), below the 25% residential coverage recommended by the U.S. Forestry Council (Figure 28.6). The full assessment of park tree species and health is available in the Parkview Gardens Parks and Open Space Plan and further assessment is provided in Appendix A. Recommendations A comprehensive urban reforestation plan is recommended to replace mature and dying trees; increase biodiversity and habitat; and increase street tree numbers and tree canopy coverage. The Plan adds approximately 900 net new trees for a total for approximately 2,300 trees of varying species for improved biodiversity. The urban reforestation plan should be an early action item so trees can mature over the time frame of redevelopment. It will increase water absorption and decrease stormwater runoff; increase tree canopy coverage to approximately 29% for energy savings; enhance walkability, pedestrian comfort and safety; increase property values; and build biodiversity and habitat. The full proposed tree canopy is depicted in Figure 28.1. National standard tree canopy coverage area (Figure 28.6) 202 Draft Parkview Gardens Neighborhood Sustainable Development Plan
Parks, Public Space, & Community Gardens Existing Parks (Figure 29.2) Figure 29.1 Analysis of Existing Conditions Existing park area is 8.86 acres, or 5.5% of the total neighborhood area (Figure 29.2, 29.3). Much of Ackert Park and Eastgate Park are paved with concrete, and Ackert Walkway is an approximately 6-foot wide sidewalk with an allee of trees along its length. Metcalfe Park is largely turf grass and dirt playing landscaping except trees. The parks have a total of 201 trees, accounting for only 17% of all neighborhood trees. Existing community gardens are a total plants (Figure 29.4). Existing public spaces include the plaza at the corner of Westgate and Clemens, Chuck Berry Plaza, the plaza on Delmar near Market Pub House and the Farmers Market, and the plaza at the Delmar MetroLink station, all of which are paved and have trees. Existing Parks Area (Figure 29.3) Existing Community Gardens (Figure 29.4) Recommendations of 14.72 acres, or 9% of the neighborhood area. While not all of the park area is planted and permeable, the redesigned parks have more space for water features, more trees and more native landscapes. Tree count in the parks increases to 585, accounting for 11.73% of all proposed trees. Trees dramatically increase water absorption and contribute to the walkability and livability of parks and the neighborhood. Community garden space increases to approximately 16,000 square feet in two gardens. It s recommended that public plazas and remaining spaces be designed with native plants, water features, rain gardens, and permeable surfaces where possible to allow for 5.0 Neighborhood Sustainable Development Plan: Blue Green Infrastructure 203
Permeable Pavement & Green Alleys Impervious surfaces of streets, alleys, and sidewalks = 28.4% of the neighborhood area. (Figure 30.3) Figure 30.1 Total Area of Impervious Surface including streets, alleys, sidewalks, and buildings = 60% of the neighborhood area. (Figure 30.2) Total Area of Impervious Surface = 60% of neighborhood area. (Figure 30.4) Analysis of Existing Conditions Streets alleys and sidewalks are currently paved with concrete or asphalt or a combination of the two. Many are falling into disrepair and need to be replaced. The streets, sidewalks, and alleys in the Parkview Gardens comprise approximately 28.4 acres of impervious groundcover, or 17.5% of the entire neighborhood area and generate and average annual stormwater runoff of 1.3 million cubic feet of water, with a stormwater discharge rate for typical rainfall events of 2.05 cubic feet per second (Figure 30.3). Many streets have parallel parking on one or both sides of the street. Sidewalks and alleys are in varying condition. Many alleys and intersections have stormwater drainage issues storm events will relieve the gray infrastructure and preserve the walkability, usability, and character of the neighborhood. No existing permeable pavement exists in the neighborhood, but permeable surfaces are being used in nearby St. Louis neighborhoods. Recommendations concrete pavement with decorative pervious unit pavers. These pavers are utilized in seven (7) foot-wide parallel parking lanes, key street intersections throughout the neighborhood, and existing alleys (images to right) This accounts for 12.1 acres 26.3% of the total paved groundcover in the neighborhood. Decorative pervious unit pavers are designed to absorb 90% of stormwater; this will reduce the average annual stormwater runoff to approximately 750,000 cubic feet of water, and the stormwater discharge rate for typical rainfall events to 1.17 cubic feet per second, a 43% improvement. decorative pervious unit paver treatment can increase the social and economic sustainability of the neighborhood by improving the appearance of the public pedestrian safety, and property values. 204 Draft Parkview Gardens Neighborhood Sustainable Development Plan
Green alleys are redesigned alleys that incorporate numerous new design features to be more environmentally and user friendly. Existing examples of green alleys in Chicago and Detroit utilize various types of permeable paving or planted pavers and native plants where possible to absorb stormwater. sunlight instead of absorbing it, helping reduce the urban heat island effect. Recycled materials, such as concrete aggregate and recycled tire rubber are also incorporated into construction to reduce raw materials use. Where possible, trees, benches, improved lighting, and bike racks are introduced to make alleys safer and more pedestrian and cyclist friendly. Figure 30.1 depicts in blue the proposed locations of permeable pavement and green alleys. Example of permeable street parking Example of permeable parking lot Example of green alley design Example of permeable paving Example of green alley design Example of green alley design 5.0 Neighborhood Sustainable Development Plan: Blue Green Infrastructure 205
Green Medians & Native Plants Existing green medians (Figure 31.2) Figure 31.1 Existing Lawns (Figure 32.2) Existing Lawn Area is 34% of total neighborhood area. (Figure 32.3) Analysis of Existing Conditions Existing planted medians exist west of Ackert Walkway in the historical Delmar Gardens area designed by Henry Wright. They do not exist east of Ackert Walkway. They are between 16 and 32 feet wide, a total of 1.48 acres, and are planted with turf grass and trees, many of them mature. Urban turf grass is about 90% impervious, so these medians account for approximately 61,000 cubic feet of annual stormwater runoff. (Figure 31.2) Urban turf grass is up to 90% impervious, contributing to increased stormwater runoff and water pollution. Turf grass requires fertilizers, regular watering, and regular maintenance using fossil fuels contributing to water pollution and poor air quality. (Figure 32.2) Approximately 56 acres, or 34.5% of the neighborhood is lawn or turf grass (Figure 32.3). Sixty percent of the neighborhood is impermeable surface including buildings, streets, driveway, parking lots, and sidewalks. This allows only approximately 5.5% of 206 Draft Parkview Gardens Neighborhood Sustainable Development Plan Recommendations The plan adds two additional green medians on the east side of Ackert and at Cabanne Avenue and Skinker Boulevard. Existing green medians are maintained and enhanced, so mature trees should be replaced according to the urban reforestation plan, and when possible, native plants will replace turf grass to increase water absorption and cut down on fertilizer and maintenance. New medians are planted with trees and native plants and grasses to match the character of the existing medians. (Figure 31.1) Native plants, sustainable landscapes, bioswales, and rain gardens should replace turf grass wherever possible. New developments minimize the area of lawn or turf grass and should be required to landscape with native or low-maintenance plants and trees. On-site rain gardens and bioswales will encouraged or incentivized. Figure 31.1 shows existing and proposed green medians in dark green and areas for native plants in light green.
Existing view of Clemens Avenue Proposed view of Clemens Avenue Existing view of an Alley Proposed view of an Alley 5.0 Neighborhood Sustainable Development Plan: Blue Green Infrastructure 207
Green Roofs Existing black roofs and white roofs (Figure 33.2) Figure 33.1 Sample green roof Sample green roof Analysis of Existing Conditions No green roofs currently exist in the neighborhood. Parkview Gardens currently has 335 black roofs, and 86 white roofs. If all proposed buildings had green roofs, the neighborhood would increase the effective permeable surface area by 18.65 acres, reducing the annual stormwater runoff by approximately 854,000 cubic meters. (Figure 33.2) Recommendations Green roofs are practical for proposed buildings but are cost prohibitive for most existing buildings. Green roofs are encouraged and could be incentivized for proposed developments. Incentives can come from various governmental bodies; organizations; partnerships between residents, the city, manufacturers, and suppliers; or collective buying programs to get discounts on various products. Figure 33.1 shows all new construction with proposed green roofs. 208 Draft Parkview Gardens Neighborhood Sustainable Development Plan
Stormwater Collection Sample rain barrel wall Figure 34.1 Analysis of Existing Conditions No existing cisterns or rain barrels exist in Parkview Gardens, but the Metropolitan Sewer District (MSD) has a rain barrel program to distribute rain barrels to residents for a discounted price. Participation begins annually in the spring. University City does not make any reference to gray water in municipal code. Recommendations Gray water collection, retention, and reuse should be allowed and encouraged in the neighborhood to mitigate the negative effects of excessive stormwater runoff. Residents are encouraged to participate in the MSD rain barrel program. Cisterns are encouraged in existing and new buildings. (Figure 34.1) Details regarding other means of bioretention such as rain gardens and permeable pavers are on page 204-207. Figure 34.1 shows new construction in light blue and existing buildings in dark blue. Sample rain barrel 5.0 Neighborhood Sustainable Development Plan: Blue Green Infrastructure 209
Blue Green Infrastructure Summary Diagram The diagrams below and to the right show how natural and built infrastructure LPSDFW WKH VWRUPZDWHU DQG HFRORJLFDO ÀRZV RI WKH QHLJKERUKRRG In the diagram to the right, orange lines represent social/equitable synergies, green lines represent environmental synergies, and blue lines represent economic synergies. The section is a representation of Parkview Gardens and is not to scale. Arts, Culture & Education Institutions Alternative Parking Bluebe sustainability education R.A.C. M O O N R Farmer s I Marke t S E rry Hill T I V O L I Lions Gates University City Civic Complex Landmarks Farmers Market open-space assets, active living, public art, community engagement, events and festivals Public Art Loop Trolley Restaurants The Loop Bike Infrastructure Community Gardens Ackert Walkway composting food waste, fresh produce reduces impervious surfaces and automobile infrastructure 210 Draft Parkview Gardens Neighborhood Sustainable Development Plan VWRUPZDWHU LQ OWUDWLRQ DLU TXDOLW\ XUEDQ KHDW island mitigation, biodiversity, open-space assets, active living, healthy living, fresh produce, food security
stormwater collection, water conservation, gray water systems VWRUPZDWHU LQ OWUDWLRQ DLU quality, urban heat island mitigation, biodiversity VWRUPZDWHU LQ OWUDWLRQ FROOHFWLRQ air quality, urban heat island mitigation, biodiversity reduced energy use and carbon emissions green buildings and sustainable sites development Mixed-Use Dev. Neighborhood Streets Green & White Roofs Renewable Energy Parks & Public Space VWRUPZDWHU LQ OWUDWLRQ DLU quality, urban heat island mitigation, biodiversity, open-space assets, active living Smart Community Infrastructure Urban Forest Housing increased open space assets improved quality of public space Green Medians, Green Alleys & Permeable Paving Affordable Housing Grocery Store North Campus Skinker Corridor MetroLink District Energy VWRUPZDWHU LQ OWUDWLRQ DLU TXDOLW\ urban heat island mitigation, biodiversity, open-space assets, active living 5.0 Neighborhood Sustainable Development Plan: Blue Green Infrastructure 211
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