Risks of Flooding (Cleveland, Cincinnati, Rocky River: 2013, condo, gardens)

[reioh]

Last year we saw massive flooding in Houston and now Cincinnati.

What are the risks of flooding in Cleveland and the NE Ohio region?

[WRnative]

Originally Posted by reioh

Last year we saw massive flooding in Houston and now Cincinnati.

What are the risks of flooding in Cleveland and the NE Ohio region?

Not high, but possible, especially in the Grand River, due to its relatively large watershed which also is prone to "lake effect" rainstorms. However, all of the northeast Ohio rivers are in deep river gorges except near their mouths, so flooding damage even during the worst storms will be relatively limited. Additionally, much land in the river gorges have been incorporated into large nature preserves, such as the Rocky River Reservation of the Cleveland Metroparks, just west of Cleveland.

The Grand River experienced a 500-year flood just over a decade ago and some of the flood plain subsequently has become parkland. Even though the river was 11 feet above flood stage, only a very small amount of developed area in the flood plain was impacted. A couple condo projects in Painesville subsequently were leveled and converted to a nature preserve, but the deep and wide river gorge capably handled an immense amount of water. Marinas in Fairport Harbor/Grand River were demolished with their boats washed out into Lake Erie.

http://www.weather.gov/cle/event_200...form=hootsuite

https://pubs.usgs.gov/of/2007/1164/pdf/ofr20071164.pdf

Lake Erie flooding always is a possibility, although Canada and the U.S. are more than willing to run more water through their huge hydroelectric facilities at Niagara Falls. Flow over Niagara Falls, currently held to 25 -50 percent of its natural flow, depending upon time of day and season, could be raised if really needed. Higher Lake Erie levels typically result mostly in increased erosion in vulnerable areas.

Flow into Lake Erie from the upper Great Lakes also can be somewhat restricted.

The most developed river gorge in northeast Ohio likely is the East and West Flats in Cleveland, in the very large and wide Cuyahoga River valley. Development includes a large steel mill, residential, and mixed use high rises. The Cuyahoga River drains a larger watershed than the Grand River, but fortunately a good portion of its length also is parkland, including the Cuyahoga Valley National Park, reducing run-off from paved over areas as experienced in Houston. The undeveloped flood plain in Cuyahoga Valley National Park and other areas certainly helps protect Cleveland and other areas downriver.

https://www.nps.gov/cuva/learn/histo...e/flooding.htm

http://www.cleveland.com/metro/index...veland_ca.html

Northeast Ohio also is emphasizing permeable ground covers, water gardens and other water retention methods, not to reduce flooding but to mitigate the flow of raw sewage into Lake Erie. E.g., many areas in Greater Cleveland can capture even a 100-year flood in their retention systems. The goal in Greater Cleveland is to eliminate 4.5 billion gallons of combined sewer overflows by 2035, reducing the overflow amount to only 500 million gallons annually.

https://www.neorsd.org/

https://www.neorsd.org/community/abo...-lake-program/

You can obtain FEMA flood maps here:

http://www.floodmap.floodsimple.com/...de709fe30d4e3c