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greatest impervious area, and our necessary reliance on infiltration and open waterways for stormwater conveyance, alternative development standards to require on -site storage and infiltration of stormwater makes sense. The unique set of circumstances in the RR/SC basin (lack of piped infrastructure, reliance on infiltration and open waterways, highly permeable soils) requires a solution that protects and enhances our natural drainage. Section 2: study area characteristics Both the city and the county have differing development standards for floodplain development and floodway development, however, "more detailed floodplain studies necessary to map floodway boundaries have not been conducted for this basin" (p.2 -17). Without these delineations, development is allowed to encroach on waterways in detrimental ways. We need development standards that will allow our natural infrastructure to meet our needs. Section 3: flood control evaluation Data collected for the computer modeling in this section was collected over an eight day period and validated for only three of those days in only one location. The effects of the resulting modeling did not match observed conditions and the data was subsequently "adjusted" to try and match real events. This is not a comprehensive data set upon which to draw conclusions for an entire basin, design major capital projects and form a course of action. In looking at table 3 -2, which details the hydraulic performance of RR/SC under present conditions and notes capacity issues for 10, 25, 50 and 100 year storms, there is no data listed for WO -005 from node 72088 continuing downstream to the end of the basin boundary. This section of the WO experienced significant flooding in the Feb. 1996 event. Stormwater rose from the storm drains to inundate the street over the curbs. In relating this to public works multiple times over the last few years in relation to ongoing development on this section of the WO, we were told that in high water events the sheer quantity of water in the Willamette River causes the WO to back up and not be able to drain into the Willamette. This anomaly is not reflected in the planning along the WO, or in the computer model which projects waterway capacity in high water events. The 1996 high water was deemed a "25 year" storm event, yet this section of the WO rose to the 374 -375 foot level, close to the" 100 year flood" level. I am concerned that this computer modeling will not reflect actual conditions. Drywells in our area were designed to accommodate a five year event. Current code requires stormwater systems to accommodate a ten year event. When rainfall exceeds the five year event, drywells become ineffective and the water is instead infiltrated where it falls, in roadside swales, in "remnanf 'waterways and identified open waterways. The data presented here shows that there are very few flooding problems associated with existing development in both the 10 and 25 year storms, yet the plan, in section 3.5.1 proposes 16 major capital projects associated with existing and future modeled capacity problems. Section 3.5.2 proposes an additional thirty-some projects associated with drywell decommissioning and rain gardens along all streets south of Horn Lane in River Rd. The modeling for future problems was done with the assumption that the drywells would be decommissioned. If that is so, how are these two lists not redundant and creating capacity for the same stormwater twice? The data presented (few capacity issues, disparity between modeled and observed conditions, ineffectiveness of drywells in carrying capacity) is not complete or compelling in light of the proposed capital projects. Plans for the other basins, completed in 2002, did not incorporate development standard alternatives. "The reason for this decision was that most of the identified flooding problems were anticipated to occur as a result of existing developed conditions. While future development would exacerbate some of the problems, a capital project to address flows from future development was more cost effective than requiring developers to address the issue through on -site storage requirements. For this basin, the conclusions from this previous analysis were assumed to apply" (p. 3 -15). The RR/SC basin plan was delayed for the last seven years in part because this basin is significantly different than the other basins. The challenges we face and the opportunities we have require us to problem solve differently than we did in the other basins. The last quote, however, clearly states that there was no analysis of the value of development standard alternatives in light of our circumstances and whether or not they are an appropriate tool for RR/SC. The data provided shows that there are few capacity issues related to existing