How to protect Bellevue from future floods?

BELLEVUE Chances are good Bellevue will flood again. Historical evidence suggests the
Cory Frolik
May 24, 2010

 

BELLEVUE

Chances are good Bellevue will flood again.

Historical evidence suggests the city and the surrounding region has experienced six massive flooding events since 1800.

Even though decades go by without incident, the water eventually comes rushing back. Until last year, 39 quiet years had gone by and then -- whoosh -- basements were overrun with water.

Residents whose homes suffered extensive flood damage last year want to be better prepared for future water wars.

They're calling on county and state officials to help obtain federal dollars for flood mitigation in the area. They also are advocating zoning rules to guarantee essential upkeep and maintenance of sinkholes, ditches and retention ponds.

It came from beneath

March 2008 was the third wettest March ever recorded in north-central Ohio.

This finding was one of the more notable ones in a recently-released report by the Ohio Department of Natural Resources' Division of Water.

During that month, about 5.41 inches of rain fell on Bellevue, Groton Township, Thompson Township and York Township.

If 30 percent of the surface rainfall found its way into the underground aquifer -- a conservative estimate -- it would have pumped about 2.5 billion gallons of water into the underground water system, said Jim Raab, geology program supervisor for the ODNR Division of Soil and Water Resources.

At 40 percent, about 4 billion gallons of water would have been dumped into the aquifer.

"We had a lot of water quickly entering the aquifer system and very little filtering through the soils," Raab said.

This huge infusion of water helps explain why last spring was a nightmare for Kenn Rospert.

Until that time, Rospert, 58, who lives on the 10300 block of Ohio 269, never would have suspected a powerful threat was lurking beneath his home.

But last spring, underground water pressure became so strong it caused Rospert's floor to explode. He spent months fighting the scourge.

Rospert's story was not an isolated case.

Homes all along Ohio 269 in Groton Township and in the northern part of Bellevue were invaded with freezing cold water. Sump pumps and sand bags did little to alleviate the problems caused by the liquid menace from beneath.

Residents spent many sleepless nights fixing hoses, monitoring pumps and dealing with water damage.

The cause

From October 2007 to March 2008, north-central Ohio received about 23.55 inches of precipitation, more than 9 inches above normal levels and about 2 inches more than the previous record set in 1898, the Division of Water report states.

All of this rain has to go somewhere, but it wouldn't necessarily lead to terrible flooding if Bellevue's geology was more like the rest of the state.

Part of the problem is the region does not have deep deposits of glacial till, state experts said.

Unlike much of north-central Ohio, which has about 50-foot thick glacial sediment, Bellevue and the surrounding region has deposits fewer than 20 feet deep.

Some parts have no glacial till, meaning nothing separates the limestone bedrock from the surface. In these areas, rainfall seeps directly into the limestone, sending it straight to the aquifer.

Heavy rainfall creates a high a water table, which then gives the surface water no place to go, Raab said. The water pushes through openings in the limestone to the surface.

The water can come up through some of the 1,000 sinkholes spread across the regions of the four counties Bellevue straddles.

Growing up in the area, Thompson Township trustee David Ziegler said he was told by his father about the karst and sinkhole system.

Ziegler said the aquifer is a fact of life that residents will simply have to deal with because there is no way to change the geological formations underfoot.

But members of the Four-County Drainage Committee -- made up largely of residents who suffered during last year's flooding -- insist steps can be taken to lessen the extent of it.

"The water table was high, I will be the first to admit it, but there are some things within our control that could ease the pain," Rospert said.

A vocal committee member, Rospert said he wants to see some ineffective ditches cleaned and brought back into working shape.

He said county officials have signaled there is federal money available to remedy large-scale drainage problems, which could pay to clean ditches and improve sinkholes. He hopes to draw up a plan for flood mitigation that county commissioners could take to the state.

Other residents also favor creating rules for future construction in the area to avoid building retention ponds, wells and anything else that could aggravate the flooding problem.

Meanwhile, the state report recommends local governments should forbid permanent structures from being erected in areas identified as flood zones.

It also recommends buffer strips and grassed waterways should be installed next to sinkholes to improve efficiency.

Lastly, the report strongly recommends the water levels in the area be monitored. The U.S. Geological Survey has loaned a device for that purpose.