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Regular Planning CommissionMeeting Minutes –Wednesday, December 2, 2015 Page 3 Mr. Lloyd advised that staff didn’t perform a comparison between previous and this latest 95 proposal.However, Mr.Lloyd advised that the arborist’s review indicated there would 96 probably be no replacement required with the trees proposed for removal and fewer 97 structures with this development proposal and based on updated tree inventory 98 information (e.g. dead trees listed in the previous inventory versus their size and 99 condition, and review by diameter breast height, of DBH, in this review). 100 Regarding staff comments and review by the DRC related to stormwater flow toward 101 Acorn Road, Member Bullsought clarification of the actual flow as displayed on the 102 grading plan.Member Bull expressed concern that the proposed infiltration basins may 103 not be empty before the next rain event occurs, causing overland flow issues.Member 104 Bull questioned long-term maintenance of the basins or how the city would address that 105 maintenance. 106 Mr. Lloyd reviewed the underground connections, overland flow, and reduced flow 107 percentages, noting that not all runoff would be overland, and as modeled, with City 108 Engineers and Mr. Mueller’s Engineer still refining the plan, maintenance of the basins 109 would be a requirement of the homeowner’s association.However, if the homeowner’s 110 association was found at fault in providing that maintenance, the City would step in to 111 address maintenance itself or by hiring a third party to do so, and then assess those 112 property owners accordingly for that cost . 113 If and when city code or watershed district standards change in the future, Member Bull 114 asked if these stormwater runoff options would be grandfathered in at the old standards 115 or if they would require updating as well. 116 Mr. Lloyd clarified that “grandfathering” was a term related to land use, but other parts of 117 code provided protections and address that ongoing maintenance and stormwater 118 monitoring via a public infrastructure contract. 119 Given the fact that this proposal includes a private road, Member Gitzen questioned if 120 that required a homeowner’s association to ensure its maintenance, even without the 121 addition of stormwater ponds and their maintenance.Member Gitzen noted reference in 122 the staff report (lines 121-123) of documents for review and approval by the City 123 Attorney, and whether or not that meant they would have input into the contract 124 language. 125 Mr. Lloyd verified that an association would be required for maintenance of the road.Mr. 126 Lloyd confirmed that the purpose of the City Attorney’s review was to protect the City and 127 its residents and advised they would revise language accordingly to provide those 128 protections. 129 Applicant RepresentativeEngineer Charles W. Plowe, PloweEngineering 130 Specific to drainage questions raised tonight by commissioners, Mr. Plowe advised that 131 the rate control would be addressed through catch basins, with the upstream pond built to 132 allow water to drain slowly with minimal if any pooling.Mr. Plowe clarified that this would 133 address the same volume of water flowing into the catch basins as experienced today, 134 but at a slower rate to avoid street flooding. 135 Specific to volume control, a concern brought up by neighboring residents in the past, Mr. 136 Plowe clarified that the rate had been slowed as well as the volume reduced, but not by 137 82%, but more in the range of 16% volume of water reduced.The reduction by 82% of 138 the rate was huge and critical.Mr. Plowe provided rationale in routing the water to Acorn 139 Road to help the volume of water flowing in to the southwest portion of the property; and 140 with this iteration, water would leave the site very slowly and infiltrate into the drainage 141 tile system, connecting to an 8” pipe and downstream into that underground system to 142 Acorn Road.Mr. Plowe advised that the City Engineer had indicated there would be no 143 problem with this additional flow with existing stormwater management in the area. 144 Member Cunningham noted that one reason for previous proposals being ultimately 145 denied by the City Council was due to concerns with emergency vehicle access; and 146