Every week when I run through the tunnel at 126th South, I can tell that the river is rising. Today, the river was at the highest level that I've seen during the past year. The path through the tunnel is usually only a few inches above the level of the water in the river, and the path was flooded soon after the river began to rise. The ground on the far side of the path rises up to the footing for the highway bridge with a slope about 20% over a horizontal distance from the river to the footing of about 12-15 feet. Today, when I reached the tunnel, I could see that the water had moved about five feet toward the footing, and at the far end of the tunnel, that is closer to the river, the water was about a foot away from the footing.
The ski resort at Snow Bird currently has over 8 feet of snow, and as that snow melts, a lot of water will go into the river via several creeks that drain the mountains. That plus any spring rains that we get have the potential to cause flooding.
Yesterday, when I ran through the picnic area south of 106th South, at a spot where the path is only about 15 feet from the river, I stopped to see how far the water was below the bank. It was about 18 - 24 inches below. If the river overflows its banks, the path will be covered, and I'll have to go back to the canal road for my running. Worse than that, there are several large office buildings and a restaurant that aren't far from the river, and they might be flooded. I don't know why people build in flood plains. About a mile downstream, there are houses being built in the flood plain.
When I lived in Massachusetts, there was a beautiful spot on Rt. 119 in Pepperell that was on the bank of the Nashua River. Some guy wanted to build a restaurant there. It would have been a beautiful spot for his business. But, the town said "no" because that area would be flooded in a serious flood that could occur every 100 years or so. As fate would have it, that area was flooded about two years later. The guy was probably glad he hadn't built there.