That’s Just Swale: Water Drainage Help for Homes on Hills

What is the purpose of a drainage swale and when do we use it?

MN realtors and homeowners, you have been waiting patiently for the description of a drainage swale. So here it is! A drainage swale is a depression in the ground designed to direct water flow. You may have found one accidentally on a country road where a depression has been made to drain water from one side of the road to the other.  Sometimes, in order to avoid this dip or depression in the road surface, a pipe is placed underneath the road so water can more easily flow through it.  This underground pipe and manhole is called a culvert.

Swales are very effective at directing water flow away from the house. Imagine if your house was on a sloping lot with the house being part way up the slope and the water flowing down the hill toward the house. A swale could be installed, by creating a perpendicular depression, at a point above the house to deflect flowing water around the house. Then, it is directed into a culvert or a second swale taking all the water from the hill to the street drain. Swales may also be bermed on the lower side to direct flow and carry more water.

Berm… swale, culvert, berm… what strange words! The swale is a strategic depression in the ground that directs water flow and a berm is a man-made rise in the ground that achieves the same thing. An example of a berm would be levees that are used to contain flooding rivers.

Previously, I stated that we could use a swale in places where we could not create 6 inches of fall, in the grade, in the first 10 feet sloping away from the foundation of the house. Imagine if the boundary line of your house was within 5 feet of the foundation and there was only 2 inches in slope to the boundary; you would not be able to achieve the code required 6 inches ground slope in the first 10 feet of fall. This could be achieved by digging a 4 inch deep swale perpendicular to the foundation, with 2% fall to the road drain. Water would flow freely to the road and away from the home foundation.

What is the purpose of the swale?  Home inspectors know and now you do too!

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

Rob ‘Pops’ Leslie
Kaplan Professionals, Retired

9 Steps for Solving Unseasonably Wet Basements

What can a homeowner or real estate agent do NOW to better protect their homes against moisture intrusion?

This question is coming up all of the time this year. 2013 is a little unique and if the home that you have owned for years, or have just purchased, has moisture in the basement; you may just be experiencing the strange end to the past winter. We have had lots of rain and freeze thaw conditions that have overcome basement protection in many MN homes. You are likely discovering that basement protection that has worked for many years has simply been overwhelmed by seasonal conditions.

Homeowners, follow these 9 Steps to prevent a repeat of this year’s conditions causing moisture problems in the lower level of your home.

  1. Clean out and cover, window wells
  2. Fill all low spots along the side of your foundation
  3. Grade the soil away from the exterior wall, to an angle of 6 inches fall, in the first 10 feet from the foundation. If you don’t have 10 feet from the foundation to an obstruction or the boundary line; create a swale. Swales will be described in the very next blog.
  4. Clean out and replace or repair any damage to gutters
  5. Make sure gutter downspouts extend at least 6 feet away from the foundation
  6. Verify the neighbors’ gutter extensions are not directed towards your house
  7. Test the sump pump
  8. Make sure the sump pump exterior discharge pipe extends at least 10 feet away from the foundation (not into the laundry tub or floor drain)
  9. Have a battery backup sump pump installed


MN real estate agents, when contracting a home inspector in the future; be certain that you have employed someone who is on top of their game and very knowledgeable about grading, drainage, and sumps. Fail to employ a knowledgeable and diligent inspector and you may pay the price in a year like 2013.

When buying or selling a home, it is important to use the services of the best MN home inspector that you can find. Do your due diligence, and be certain that you are employing somebody who doesn’t miss the details. Ask yourself…

Can this inspector find the elusive signs of occasional water problems as well as all the other issues found in today’s homes?

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

Rob ‘Pops’ Leslie
Kaplan Professionals, Retired