Item 9: Ordinance Concerning Stormwater Development Standards

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Comments on Stormwater Development Ordinance and Stormwate Page 4 of6 controls section (9.6795) says its purpose is to "prevent stormwater pollution..." This does not seem accurate if the Manual's definition of storm water is assumed. The Public Works definition would be more appropriate. Or, it would be more accurate to say that the purpose of source controls is to prevent pollution of runoff. But only if "runoff' is also redefined, as above! Destination Standards * The Stormwater Management Manual (Section 1.4.2 Destination Design Methodology) states that the City has developed a flood control strategy for each of the drainage basins within the UGB, and published these within the 2002 Stormwater Basin Plans. Yet the River Road-Santa Clara Basin Plan has not been finalized due to problems with the modeling and verification of various aspects of our drainage system. Without correct drainage modeling, it does not seem possible to gauge the necessity and sufficiency of recommended development standards and capital projects at controlling flooding in our area. * The Draft River Road-Santa Clara Basin Plan says that flood control goals could be met through standards for reduced effective impervious surfaces, and infiltration and detention areas. However, the proposed ordinance does not include such flood control development standards. Evidently it is City policy to NOT implement flood control development standards, but to assume that capital projects in each Basin will be sufficient to control flooding. We have been unal1le to learn the justification for this. Yet, with the amount of density slated for (and already arriving in) River Road, and the desirability of preserving the natural drainage system, it seems appropriate that reduced effective impervious surface and infiltration standards be considered. It seems especially premature to reject such standards when the drainage modeling is not complete for our Basin. Can staff explain the reasoning for this? * Given that most of River Road and Santa Clara is not served by public storm sewers, developers should be required to select as the destination for stormwater either "on-site infiltration" or "off-site discharge to surface flow", and NOT "off-site discharge to piped flow". In the same way that the ordinance specifies preferred use of on-site filtration in the Headwaters area, it should specify preferred use of on-site filtration in River Road and Santa Clara. This is important because of the lack of storm sewers, and also the importance of recharging groundwater. * Developers should be required to retain natural ~ydrology, and use soil Best Management Practices, minimal site disturbance, and other low-impact development (LID) techniques to prevent stormwater runoff in the first place. We urge Council to ask staff to develop a set of proposed LID standards to address these aspects in future amendments to the development code. LID techniques will reduce runoff, and thus reduce the need for off-site discharge of stormwater in the first place. Pollution Reduction Standards * Pollution reduction provisions in the ordinance apply only to development that results in more than 3000 sq. feet of additional impervious surface. Why would these standards not be applied to ALL development, including single family dwellings? The pollution impacts of development are the same whether the development occurs in one large piece, or many smaller pieces. If the intent is to exempt development with truly minimal impact, then exemption of development that adds less than 500 sq. ft. of impervious surface might be more justifiable. The 3000 sq. ft. exemption seems to offer a loophole large enough to allow developers to avoid the requirements of the ordinance entirely by simply subdividing large areas and developing each parcel as a separate (single-family dwelling) application. [Putting the exemption at 3000 sq. ft. because that figure is also used in setting stormwater rates or fees is not very compelling, and bears little rational relationship to the purpose of this ordinance, which is to protect water quality and prevent flooding]. Please reduce this exemption to 500 sq. ft. 5/23/2006