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RCA Exhibit A 5 � Member Murphy noted that water runoff from the subject site to neighboring properties had continued to 52 be of great concern in past iterations, and asked staff if this iteration was implemented as designed 53 indicated only 18 gallons of stormwater runoff. Member Murphy asked if there would be any cost to the 5� city for connecting and diverting stormwater flow to the Acorn Road system or if it would borne entirely by 55 the developer. 56 Mr. Lloyd clarified that runoff was measured by cubic feet per second, not gallon, and confirmed that 100 57 year rain event model numbers indicated that would be the case and as compared with typical rain events 58 where stormwater runoff should easily be addressed through infiltration of one mode or another. Mr. Lloyd 5S confirmed that the cost to divert stormwater flow to the Acorn Road infrastructure would be at the cost of 6o the developer to implement. 6� Member Murphy asked staff for a comparison with this latest tree removal plan with that of the most 62 recent past iteration. 6: Mr. Lloyd advised that staff didn't perform a comparison between previous and this latest proposal. 6l However, Mr. Lloyd advised that the arborist's review indicated there would probably be no replacement 65 required with the trees proposed for removal and fewer structures with this development proposal and 66 based on updated tree inventory information (e.g. dead trees listed in the previous inventory versus their 67 size and condition, and review by diameter breast height, of DBH, in this review). 6� Regarding staff comments and review by the DRC related to stormwater flow toward Acorn Road, 6� Member Bull sought clarification of the actual flow as displayed on the grading plan. Member Bull 7o expressed concern that the proposed infiltration basins may not be empty before the next rain event 7� occurs, causing overland flow issues. Member Bull questioned long-term maintenance of the basins or 7� how the city would address that maintenance. 7� Mr. Lloyd reviewed the underground connections, overland flow, and reduced flow percentages, noting 7� that not all runoff would be overland, and as modeled, with City Engineers and Mr. Mueller's Engineer still 75 refining the plan, maintenance of the basins would be a requirement of the homeowner's association. 76 However, if the homeowner's association was found at fault in providing that maintenance, the City would 77 step in to address maintenance itself or by hiring a third party to do so, and then assess those property 7z owners accordingly for that cost . 7� If and when city code or watershed district standards change in the future, Member Bull asked if these 8o stormwater runoff options would be grandfathered in at the old standards or if they would require updating 8� as well. 82 Mr. Lloyd clarified that "grandfathering" was a term related to land use, but other parts of code provided 83 protections and address that ongoing maintenance and stormwater monitoring via a public infrastructure 84 contract. s5 Given the fact that this proposal includes a private road, Member Gitzen questioned if that required a s6 homeowner's association to ensure its maintenance, even without the addition of stormwater ponds and 87 their maintenance. Member Gitzen noted reference in the staff report (lines 121-123) of documents for 8g review and approval by the City Attorney, and whether or not that meant they would have input into the 8� contract language. 9U Mr. Lloyd verified that an association would be required for maintenance of the road. Mr. Lloyd confirmed 9� that the purpose of the City Attorney's review was to protect the City and its residents and advised they 92 would revise language accordingly to provide those protections. 93 Applicant Representative Engineer Charles W. Plowe, Plowe Engineering 9n Specific to drainage questions raised tonight by commissioners, Mr. Plowe advised that the rate control 9� would be addressed through catch basins, with the upstream pond built to allow water to drain slowly with 96 minimal if any pooling. Mr. Plowe clarified that this would address the same volume of water flowing into 97 the catch basins as experienced today, but at a slower rate to avoid street flooding. 98 Specific to volume control, a concern brought up by neighboring residents in the past, Mr. Plowe clarified 9�. that the rate had been slowed as well as the volume reduced, but not by 82%, but more in the range of 10c� 16% volume of water reduced. The reduction by 82% of the rate was huge and critical. Mr. Plowe Page 11 of 15