6.5. SR 08-21-2000 - Laserfiche WebLink

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Mr. Steve Wensman July 13, 2000 Page Two The temporary drop-off spot shown in front of the church building with Phase I is in a poor location. This is the only spot for circular traffic around the large parking island. If this is a drop-off location, there will be conflicts between vehicles stopping to drop people off and vehicles wanting to circulate around the parking stalls. Perhaps a couple of parking stalls in front of the church could be deleted in Phase I and that area used for the drop-off site. C. Preliminary Grading Plan There is a relatively steep slope on the south side of 217th Avenue. The grading plan shows leaving that in place. Phil Hals, Street Superintendent, has indicated that he would like to see that slope removed with a gradual grade into the church site. We have just received drainage calculations and have not had time to review them. However, the concept of the drainage of the site is questionable. Basically, the drainage is being picked up in the northern parking lot and conveyed to the County ditch. Then the County ditch is being used as a portion of the storm drainage conveyance system to the southwest corner of the site where a culvert directs drainage from the County ditch into a holding pond. We question whether or not the County would even allow this type of drainage pattern. Here are the other questions we have: Are there any culverts under CSAH I that would outlet this drainage? What will happen if CSAH 1 is rebuilt and the drainage ditch adjacent to it redefined? We believe that the drainage for the church should be contained totally within its site and not rely on the County ditch system. The drainage pond in the southwest corner is partially within the County right-of- way. This pond should be moved to the east to eliminate the encroachment into the right-of-way. Also, the slopes of this pond are a 3:1. This is a pond that will hold water and has no outlet. We would suggest that the pond's slopes be 4:1 or flatter. Certainly with a thirty-acre site, there is enough room to move the area to the east and allow a larger area with a flatter pond slope. It is unclear whether the entire site will be graded at once or will be graded in phases with the building. If it is to be graded in phases, there should be a phase line shown on the grading plan. If it is to be graded in phases, the storm drainage pond needs to be included with Phase I. The grading plan shows concrete curb and gutter along the front of the church and around the parking lot islands. The remaining perimeter of the parking area is proposed to be bituminous berm. We question whether this is acceptable. The site should be graded to eliminate the need for the catch basin immediately to the east of the Phase I building. At a minimum, an emergency overflow elevation needs to be shown here so that drainage beyond the catch basin capacity will get into the parking lot area and not into the building. With the access point onto CSAH 1, the grade is downhill to the road. The road appears to be at a 967 elevation, and the lowest contour shown on the access is 966. It is unclear how drainage will be taken from the Iow point off of the road Ltr-071200-Wensman.doc Howard R. Green Company CONSULTING ENGINEERS