More About Swales: With Great Benefit Comes Great Responsibility

Are swales and culverts used often for drainage? 

Yes they are! Swales are often dug along property lines to direct water to street drains. Most people aren’t aware that there is even a drain there. They don’t take any particular notice of the depression in the soil and think nothing of it, when all of the water between the houses is directed to the storm drain instead of leaving pools on their property.

Take a look at this illustration of a swale and then the photograph of 10 properties that are swaled to a single culvert! What a wonderful solution to getting water off the properties… Maybe!

What if some of the 10 property owners leave trash in their swale depression, which is washed down to the culvert anytime it rains? Is anyone in the community going to be responsible for seeing that there is no trash building up on the grid during rainfall? Trash or debris building up on the culvert grid can become a very effective plug. A pond can be formed very quickly, behind the culvert opening, in heavy rainfall, which can in turn raise the water table on the surrounding land. Hopefully the drainage designer has allowed for such a possibility and has designed the residential lots, so that a rising water table will not flood the basements of the surrounding homes or cause the sump pumps to be operating continuously.

Swales are marvelous, but they do require maintenance and supervision. You can’t allow a swale on your property to build up with debris to a point where it causes water to flow onto the neighbor’s property or perhaps in the direction of your own basement. It is simply illegal to allow water to flow off your property on to your neighbors land and I’m sure you don’t want to wake up one morning with a wet basement yourself!

We would appreciate hearing from you, if you have an opinion or a question on swales. In fact, we would like to hear from you anytime you have a comment or an idea to share on any of these blogs. Communication is a two-way street, so let us hear what is going through your mind.

Doug Hastings
MN Home Inspector, Minneapolis & St. Paul
Kaplan University, Home Inspection Lead Instructor

Rob ‘Pops’ Leslie
Kaplan Professionals, Retired

Moisture Problems – Hardscaping (Part 5)

Although landscaping is so very important to a dry basement, sometimes other things outside the home can cause water to work its way inside. Because of difficulty and cost, people are often hesitant to consider the negative impact hardscaping can have on moisture intrusion. What I’m talking about here are:

  • Walks
  • Steps
  • Patios
  • Decks
  • Driveways

Just like the earth, over time these wood, asphalt, and concrete surfaces can settle. Often the settlement will either puddle water alongside or actually drive water towards the foundation. As I said these hard surfaces can be expensive to remove and replace. For this reason, most of the time, homeowners will leave the settled hardscaping and try anything and everything else to try to correct the problem…and it never works! There is a core principal here and that is, if water is being driven towards the foundation, at some time, it is bound to come into the basement. It might not be in normal rain or snow thaw, but during in-climate conditions it will.

That’s why if you ask a homeowner selling their house if they have moisture in the basement, their immediate reaction will be no. Then when they think about it for a moment, they will say something like well maybe a little bit on real heavy rainfalls or only when the downspouts are disconnected or only when it rains really hard from the north. What they are saying is the landscape and hardscape are not sloped adequately to handle large volumes of water. Homeowners, home buyers, and real estate professionals don’t expect basements or crawl spaces to be dry some of the time or even most of the time. Today, these people demand that these below grade spaces be dry ALL of the time.

So the grounds surrounding the home are very important to protect against moisture intrusion…but that’s just the beginning!

Doug & Julie Hastings
Your House Whisperers
Minnesota Home Inspection Services