Laserfiche WebLink
Money Does Grow on Trees! <br />Investing in Ramsey's Streetside Urban Forest <br />/ / / / <br />1/1 <br />• <br />Improving <br />Runoff <br />Drainage <br />Rainfall Interception <br />A tree will absorb more water <br />as its Diameter at Breast Height <br />(DBH) increases. However, water <br />interception also varies by species. <br />In areas that experience heavy <br />runoff, oaks would be effective <br />at intercepting large volumes of <br />water. However, oaks grow large <br />and may not fare well in narrow <br />spaces. Ginkgos can grow large, <br />but they are slower -growing and <br />would be more appropriate in <br />confined spaces. In small planting <br />spaces with less runoff, small trees <br />like crabapples would be a good <br />alternative. <br />Prototypical perspectival section <br />Stormwater <br />Each year, Ramsey receives 14 to 15 billion gallons of rainfall. New development expands impervious <br />surface area, which includes surfaces like parking lots and roofs that are impenetrable by <br />water. Stormwater systems mitigate flooding by channeling rainfall to stormwater ponds and other <br />surface waters (e.g. wetlands, lakes, and rivers). <br />However, runoff contaminates surface water when it carries oil, litter, and other pollutants. Trees <br />improve stormwater management by promoting infiltration (movement of water into soil), which <br />helps filter pollutants and recharge aquifers. <br />More development means less surface soil for water infiltration; trees make <br />Annual Rainfall <br />up for this loss by intercepting water and promoting infiltration. <br />Oak <br />Ginkgo <br />Crabapple <br />751 gallons <br />38 ft' <br />This tree intercepts 751 gallons of rainfall in a <br />year, equivalent to the annual rainfall received <br />by 38 if of soil in Ramsey. <br />220 gallons <br />11 ft' <br />Stormwater Flow <br />OStormwater flows into <br />inlet <br />OWater distributes and <br />infiltrates through soil <br />OTree roots take up and <br />hold water <br />Filtered and excess water <br />flows through pipes into the <br />stormwater sewer. <br />4111111 <br />Prototypical perspectival section <br />Optimizing Stormwater Systems <br />1 In the COR, tree pits <br />combine with planters, <br />and these connect <br />to stormwater sewer <br />7 inlets. This maximizes <br />the runoff capture from <br />direct rainfall and inlet <br />flow. <br />Common Issues <br />Water pools away from <br />drainage sites <br />Trees lacking moisture <br />and oxygen send roots <br />to the surface <br />Compacted soil and <br />Cinsufficient root space <br />prevents stormwater <br />absorption <br />Trees underperform in poor <br />site conditions <br />Permeable pavers <br />enhance street tree <br />systems by allowing <br />water to pass through <br />small spaces in the <br />sidewalk. This ensures <br />that more water moves <br />into the soil instead of <br />pooling away from <br />trees. <br />Trees Protect Our Cities from Storms <br />No one wants to be caught unprepared in a rainstorm. Fortunately, street trees are on the first line of defense <br />when it comes to intercepting stormwater pollutants. Next, we see how Ramsey can utilize street trees to improve <br />air quality by filtering pollutants and reducing pollutant emissions. <br />PA 5211 Land Use Planning • TEAM: Ada Moreno Gomez, Nick Kieser, Victoria Dan • INSTRUCTOR: Fernando Burga, Ph.D. UN[veasirr of M[NHesoTa <br />