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Comments on the River Road / Santa Clara Stormwater Basin Master Plan from the River Road Community Organization. October 23, 2009 Dear Therese, These comments are submitted on behalf three members of the RRCO Executive Board. There has not been time to share the information in the Basin Plan with RRCO's full board or membership or the broader neighborhood during this comment period, nor have we been able to solicit feedback or take any kind of vote on its content. Overall, we are very disappointed that the proposed Basin Plan does not assess or recommend low impact development (LID) standards for our neighborhood -- standards to reduce the percentage of impervious surface and development footprints, protect well- draining native soils and "country- style" drainage systems, and protect large trees. It also does not discuss downspout disconnects or rainwater catchment systems, topics raised by RRCO members at past meetings about the Basin Plan. LID standards are desirable not only for stormwater management, but also to protect neighborhood character and broader environmental values. RRCO and residents of our area have been asking for such standards for many years - -during the Transition Project meetings and other processes and venues. As noted in the Executive Summary, each drainage basin offers unique conditions and opportunities for implementing development standards. Yet this plan ignores previous public input, and does not use this opportunity to propose unique or specific low impact development standards for this basin. We are also disappointed that neither this Plan nor existing City -wide stormwater standards (whether for private development or public capital projects) require on -site infiltration to the maximum extent feasible, as is required in Portland, nor require non - structural best management practices first, before use of engineered facilities. We are also very concerned that the proposed local street designs - -with sidewalks, wider lanes or parking bays, and on- street rain gardens - -are much wider and pave much more land than our existing local streets. Such streets would dramatically alter the character of our neighborhood, lead to loss of large trees and landscaping, and likely involve costly assessments to adjacent property owners. We believe that they would also encourage faster driving and greatly reduce the effective pedestrian zone relative to our existing "shared space" streets. There must be less expensive and intrusive ways to manage stormwater runoff from our streets. More options need to be evaluated (shared space and skinny streets, pervious /porous surfacing), and the public needs much more opportunity for involvement in designs for our local streets. Section 3: Flood Control Evaluation 3.2 -3.4 Model validation, results, and flooding problems This plan compares model results with actual conditions at just one point during one 3 -day rainy period. This does not seem like enough data to validate a model over the entire basin. Also, the model results at this one point do not correlate well with actual observed conditions, even after "adjustments " -- actual drainage is considerably better than predicted by the model. It seems that more work is needed to truly validate the model, or it may lead to over - predicting flooding problems and over - sizing of stormwater facilities.