Item 9: Ordinance Concerning Stormwater Development Standards

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Existing systems designed by nature that control flooding, protect water quality, provide aquatic habitat, make an area more livable, and increase in value and effectiveness over time are priceless and perform at significantly higher levels than their engineered replacements. While the manual states its goal is to "provide storm water management principles and techniques that preserve or mimic the natural hydrologic cycle and achieve water quality goals", the entire ordinance and manual focus on the "mimic" and not the "preserve". They are written with the assumption that development which compromises our existing natural drainage systems will occur and that we will somehow "mitigate" the effects through artificially constructed stormwater "facilities". The amount of soil compaction that occurs when we construct something to mimic natural systems greatly reduces the effective rate of percolation for the entire disturbed area. Instead we should look at "Low Impact Development Standards" LIDS or "zero impact development standards" ZIDS (see definition at end of document) that are increasingly adopted in other cities. They are superior for meeting stormwater management goals and also have the added benefits of saving infrastructure costs, long term maintenance costs, preserving livability, and protecting natural resources. The ordinance does a good job of protecting the headwaters area, but needs to offer the same level of protections to other sensitive areas. The River Road/Santa Clara basin does not have the infrastructure necessary to accommodate the level of urbanization the city allows through its zoning. In order for us to continue to urbanize, we need the ordinance and the manual to protect our system by: . Requiring protection of existing natural drainages. The filling of our swales and wetlands to accommodate more housing which discharges polluted stormwater runoff directly into our open waterways does not meet the goals ofthe ordinance. We have no alternate storm sewer system to fall back on. . Limiting the amount of impervious surface. We are experiencing rapid development with high levels of impervious surface and no way to treat, capture, and retain the runoffbefore it discharges directly to the open waterways. "At 34 percent, the basin currently has levels of imperviousness that are expected to degrade water quality. Projections at UGH buildout indicate that the impervious surface area will increase to 51 percent, which is the highest for all the basins. JJ (RR/SC draft basin plan p.2-20). . Instituting "Green Streets" to minimize the pollutant levels from roadways. Roadways are the single biggest source of stormwater pollution and runoff. . Green streets are narrower, have no curbs and gutters, and are bordered with bioswales to slow conveyance of the water and allow for surface biofiltration. . Protecting native vegetation, and existing trees. Large shade trees intercept huge volumes of stormwater-thousands of gallons-yet too often they are cut down as part of new developments or street "improvements". Developers commonly remove all native vegetation from a site and fill existing drainageways, dramatically reducing their ability to filter and retain stormwater. . Protecting native soils. The soils in the RR/SC basin are generally well drained and allow tremendous amounts of groundwater infiltration. They effectively filter stormwater runoff and allow for the recharge of our groundwater system supplying