Basement Waterproofing in Bellevue, Ohio

Bellevue is unusual. The city sits on the Bellevue-Castalia Karst Plain, where limestone bedrock is riddled with cracks, channels and sinkholes. Instead of running off in streams, much of the rain soaks into the rock. When the groundwater rises, it has nowhere to go but up.

That's exactly what happened in 2008. In February, more than 200 homes experienced flooding, and State Route 269 was underwater from February into June. By March, groundwater reached its highest level in 40 years, and sinkholes discharged water like springs. Homeowners pumped for weeks, some basement floors buckled, and the city spent about $500,000 on the response.

Bellevue at a glance

What karst means for your basement

In most towns, basement water comes from rain soaking the soil around the house. In Bellevue, the water table itself can rise high enough to push water up through the floor and in at the wall joint, even in homes that stay dry most years. Groundwater floods here can also last for weeks, not hours.

That makes reliable pumping the priority: a properly sized sump pump, a battery backup, a high-water alarm and a discharge line that carries water well away from the house. Ask contractors specifically about their experience with groundwater in the Bellevue area.

• Look at the joint where the wall meets the floor after a heavy rain. Damp lines there usually mean water pressure from outside, not a plumbing leak.
• Check block walls for white, chalky deposits (efflorescence). They are left behind by water moving through the masonry.
• Walk the outside of the house during a storm. Downspouts that dump next to the foundation are one of the cheapest problems to fix.
• If you have a sump pump, pour a bucket of water into the pit and make sure it starts, empties the pit and shuts off.