How to drain your rain-caused 'lake'

The easiest way to direct runoff away from a home's foundation is with a downspout extension. But depending on the landscape, the location and the home's footprint, a more permanent drainage solution may be necessary. (Photos: Kathy Morrison)

The aftermath of Sunday’s record rainfall was a physical reminder of a basic law of nature: Water tends to accumulate at the lowest spot. If you didn’t know where that was in your yard, you do now

So much rain after years of so little created instant lakes in landscapes that are now taking days to drain.

Where did all this water come from? Often, off your roof.

Rain gutters – in particular, the misdirection of runoff from those gutters – can lead to drainage problems. Typically, downspouts run straight down off the roof to the ground – ending close to the house and foundation. That causes water to pool around the building and potentially leak inside into basements or crawl spaces.

The solution: Extend the downspouts away from the house and foundation. Ideally, the extensions should take rainwater at least 10 feet away from the house.

If that’s not enough, a “perimeter drain” – a gravel-topped trench around the house – can help prevent water from getting into basements or crawl spaces. This drain redirects the water to a safe release point away from the foundation.

A similar technique is a “French drain” – a buried perforated pipe that collects water and directs it away from the low spot.

Despite the name, French drains have nothing to do with France. According to experts, these unusual drains were invented by an American, Henry Flagg French. He popularized them in his book on agricultural drainage, published in 1859 in Massachusetts.

Such drains can be simple to install – dig a trench, put it in – but must be strategic. (Where do you want the water to go?)

The drainage aisle of a local Ace Hardware store was looking picked- over Tuesday, but these NDS catch-basin drain grates were still in stock.

Water tends not to drain well through clay; that’s why the backyard “lake” formed in the first place. If you cover the French drain with clay soil, it plugs up the drain and doesn’t give it a chance to work.

Instead, backfill over the drain with sand, gravel, decorative rock or other fast-draining material.

Use that clay dirt to form berms to redirect rainwater away from the house and to that gravel-covered French drain.

Those berms also could form a “rain garden,” catching stormwater and allowing it to soak in where you want it – not next to the house.