08-20-18 Health and Public Saftey & Utilities

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CITY OF SOUTH BEND I OFFICE OF THE CLERK discharges a little higher up. These are lower given the topography out here,you couldn't go much higher with them. Mr. Metters detailed the survey responses in the (referencing a slide in the presentation). He explained,During the less extreme events,there are some potential areas that need to be looked at. The river got up high and flooded the ground surface in the area and brought the ground water up. The primary source of flooding was cracks in the floors and walls. Thirty-five (35) of the one hundred five (105) had backflow prevention devices. Of those, twenty-one (21) noted that they worked properly. I questioned why it was that fourteen(14) didn't work properly. One (1) of the other areas that had major flooding happen, was a private property on which we did a field investigation. The blue lines on the map (referencing a slide in the presentation), represent flow paths. This water is flowing down to the southwest towards the river, and there is a steep area, so it is coming very quick, then the water wants to flow out between some of these residences. That is about forty (40) acres of water that is draining unrestricted. Some of that is county area and some is within the city, and it is a private landowner. He went on,Based on the GIS,we had some areas where there were larger pipes falling into smaller pipes. They were eighteen (18) inch pipes flowing into ten (10) inch pipes. We went out and made sure the GIS was correct and it was. That doesn't necessarily mean that the ten (10) inch is undersized. There was very little flow coming from that larger pipe, and the ten (10) inch could be at a different slope. There are a lot of different variables that go into sewer design. What tends to be missed a lot is that most of the infrastructure we're talking about is under ground. People were worried about the flooding on the surface, and rightfully so. At what point do the pipes in the system reach the elevation of the river? He pointed out a yellow and black line (referencing a slide in the presentation), which shows how far back the sewers were inundated with river water. The whole neighborhood had sewers backed up, and that tended to be the same in the Riverside and Keller Park areas. He continued, Also, the City had crews out shortly after the event, videoing the sewers, sewer pipes and the storm and sanitary lines. We got those videos and went through and rated the pipes. There are some areas, where there was some potential clogging or cracks in the pipe. It might not be the whole line, but the red lines on the map (referencing a slide in the presentation) indicate those possibilities. He then presented the EmNet Data for CSO four (4). He explained, On February 19th, it started to go up. It didn't go back down until May5th. When a storm like this happens, you can't just look at a localized area. It is a system-wide event. This was at capacity. We could have had bigger pipes in some areas, but there would still have been nowhere for the water to go, because the storm has exceeded the capacity of the network. He went on, Less than fifty percent (50%) noted having backflow prevention devices, and there was only a small percentage that stated that they worked. There are several reasons why they may not have worked. Several residents from this area also noted that earlier notification would have been helpful. A majority of the pipes within this area had been televised, which provided an opportunity for us to look at those pipes. There were some parts that appeared partially obstructed to flow. We noted the ten(10) inch pipe, the heavy flow and flooding from the area north of the residences, and that there are several storm outlets along the river in the North Shore Triangle area. None of those outlets are outfitted with backflow prevention devices. EXCELLENCE I ACCOUNTABILITY I INNOVATION I INCLUSION EMPOWERMENT 455 County-City Building 227W Jefferson Bvld South Bend,Indiana 46601 J p 574.235.9221 f574.235.9173 TTD574.235.5567I www.southbendin.gov 6