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stormwater runs into the pond, it picks up particulates that settle out in the ponding area. Therefore, when the stormwater goes downstream it is purer and better water. The pond would allow plant growth that removes nutrients from the stormwater. The water would be released to a storm sewer that runs to northeast toward Rice Creek. The standard for this type of national urban pond is being developed to enhance water quality. First, G & P would develop a water pond that would have water in it most of the time, except in very dry periods. G & P may put a bridge across the pond at some point in time to enhance the aesthetics and to connect to the park better. The pond would be on the northwest corner of the existing building. The existing storm sewer seems adequate to handle a ten-year storm event. That is about an inch and a half of rain over a 24-hour period. The storm sewer is not designed for a big storm such as we had this year. Now, during a large storm, a dam forms outside the storm sewer pipe at the corner of the proposed building. When the pipe cannot carry the flow of the water, the water builds up behind it. The pond would be designed to hold such water. The existing pond is not large enough to hold large amounts of water. Therefore, temporary flooding occurs around the neighboring homes. G & P wants to eliminate that situation. The plans have taken the existing storm sewer system and opened up the embankment between the ponding area and the park. During a large storm, the water would begin to build up in the ponding area and would run across the park and into the new ponding area. Clark is designing the pond to handle stormwater for a hundred-year event. Harrison stated the constructing the new pond would entail significant changes. The stormwater needs to be captured by additional piping and taken over to the new ponding area. Areas on the adjacent properties are too low to pipe all the stormwater away from those properties. G & P needs to get permission from the corner property owner to allow them to build a manhole, fill the area and let water from the larger storm run across the park and into the ponding area. If G & P is unable to get this permission, some ponding would occur on that property because of the open pipe dumping into that corner. A pipe outlets the water to a bigger pond, but there would be more localized ponding if we do not get this permission. G & P hopes they can work with the neighbors to eliminate all the low area next to the proposed Alzheimer’s wing. Karen Chandler of Barr Engineering showed aerial photos of the site showing the drainage in the area. Chandler pointed out the present drainage features. Chandler said that, besides the pond becoming too full, the present grading is causing the water to drain through the adjacent properties. Chandler explained the drainage way would be well-defined by the new plan. The well-defined feature would be critical to the adjacent homes. Chandler stated that the proposed stormwater management plan would be a benefit to the community because it improves water quality. Rice Creek would benefit from the improved water. Schiferl asked Chandler to explain the issue on the corner lot. Chandler showed the present ponding area on the overhead photo and the low spots on the adjacent properties. Chandler said the property owners would not be losing any property, but would be having their lot regraded. Harrison said, if G & P does not receive permission to regrade the neighbor’s property, a large storm would put from two to three and a half feet of water on the property. G & P wants to fill that area, which would amount to giving the property owner a backyard. Currently, the property drops two and a half to three feet away from the home’s deck. The backyard would be level if the lot is regraded. A manhole would be on the property. When there is a storm heavier than a ten-year event, which is what the storm sewer is designed for, water would raise one foot before it runs across the park. When the rain subsides, the water would go into the manholes and run out of there. More than one foot of water would flow across the park. Longworth showed the proposed modified berm. Baker referenced Chandler’s comments on a more defined area. Baker asked if Chandler were talking about surface water. Chandler responded affirmatively. Chandler said the water flowed in two directions. Some water goes overland and some of it is captured in pipes. Catch basins carry the water into a pipe and some water flows overland in a drainage way. That drainage way is not well defined now. I:\COMMISSIONS\PLANNING\MINUTES\1997\10-21-97.WPD 3