How to Minimize Flooding and Water Damage in Heavy Rain

Quick Column Summary:

• Flooding from record rainfalls
• Combined storm and sanitary sewers
• Soil can only hold so much water
• Store valuables above flood lines

Long Island was battered with record rainfall last week. It caused both physical and emotional damage to tens of thousands of residents and businesses. If you were one, I'm so sorry for your losses and can only now offer advice to prevent it from happening to you in the future.

My college degree is in geology and two of the areas that fascinated me were geomorphology and hydrogeology. Geomorph, as we called it back then, is the study of the shape of the earth. Hydro, is it was known by underclassmen, is the study of groundwater. If you were a victim of flooding, both of these subjects should be of keen interest to you.

I've also been a licensed plumber for over thirty years and know a few things about buried pipelines, both in homes and storm sewers in city streets. In some older communities, it's common for the storm sewers to be combined with the sanitary sewers.

Historic storms in cities and towns that have these combined sewers can cause raw sewage to backup into the basements of homes when the sewer lines become supercharged with rainwater that pressurizes the sewer pipes.

The first thing you should realize is that normal soil can only hold a given amount of water. There's just so much air space in top soil. When the top soil fills with water, any remaining rain begins to travel over the surface of the land. If your home is in a low spot, a catastrophic storm can cause that low area to become a wide river as the rain water makes its way to the ocean.

Storm sewers are not designed to handle historic rains. To do so would be far too costly. If your city or town has combined sewers, realize that your basement can fill with murky polluted water in an hour or less as water shoots up through floor drains or bubbles out of basement toilets and sinks.

Anything in that space will be ruined. Water can rise so fast that you'll never have time to carry valuable things to the first floor. What's more, the water can become energized with electricity if the water rises and floods wall outlets. It then becomes dangerous to be in the rising basement water trying to carry things to the first floor.

Water flowing through your yard can also rise up against your home and burst basement windows. I once saw a basement fill with water in less than two minutes from a flood like this. It was terrifying.

The bottom line is that you'll never stop the water if a huge storm strikes again. I don't care how many sump pumps you install. I don't care if your gutters are clean. I don't care if you slope the water away from your foundation.

To minimize damage, you need to have a pre-action plan that causes you to store any valuable tools, property or keepsakes up above any level that might be flooded. With modern weather forecasting you can often know that bad weather is coming and have time to move objects in your home to a safe spot. But sometimes the forecasters and sophisticated prediction software simply can't outsmart Mother Nature and a catastrophic storm can happen with little notice.

To be completely safe, consider storing your most valuable things in a secure garage or shed. Be sure the items are up on shelves and not on the ground. It's a common sense thing, but all too often people just put things on the floor of basements, garages and sheds.

Sturdy shelving is easy to build or you purchase metal shelving units that assemble with no tools. Store valuable items in waterproof plastic containers that have secure lids that will allow the bins to float if the water rises above a level that you feel is safe. Large ten-gallon containers are quite inexpensive and can offer significant protection.

While the photos and videos are still fresh in your mind, look at them again. Note the areas that were hardest hit by the flooding. If where you live has the same topography and didn't get as much rain, the heavy rain belt may affect you the next time. Don't assume you'll be dry and safe in the next huge storm.

This information was shared with the 31,000 subscribers who read Tim's January 29, 2019 AsktheBuilder Newsletter.

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