1019 112TH ST SW 2019-09-25 - Laserfiche WebLink

Community Health Center Upstream Analysis The site appears to receive runoff from forest and lawn areas on adjacent parcels to the west. No erosion or concentrated flows were observed from adjacent runoff. Downstream Analysis A downstream analysis was provided by Timothy Sarkela, E.I.T. of Western Engineers on November 27, 2017. Refer to the aerial map in the next section of this report for a depiction of runoff paths. The northern acre of the project property tends to slope southeasterly toward a low point along the east side of the property approximately 450 feet north of 112th Street SW. This runoff is then collected by an existing catch basin approximately 5 feet east of the eastern property line. The runoff then continues approximately 330 feet southeast through a County documented drainage system before daylighting into a tributary of Swamp Creek. The remainder of the property tends to slope southerly toward established on-site drainage systems that are conveyed to an on-site drainage system and outlet to the public drainage system along the north side of 112tH Street SW. According to County drainage maps,runoff is then conveyed approximately 100 feet south within the public system before daylighting into a tributary of Swamp Creek. Because both runoff paths leaving the site are less than 1/4 mile to Swamp Creek,they are considered to be within the same drainage basin. Drainage Complaints There are no known drainage complaints for this property. WESTERN ENGINEERS,INC. 4 PROJECT:17-1688-A