Outdoor Drainage Project: Backyard Hill Sloped Toward Backyard in Minnetonka, MN

The Drainage Problem: Backyard Hill Sloped Toward Backyard

This customer called because water was running down a large hill in their backyard toward their house. This water issue caused erosion damage to her plant bed and boulder retaining wall. The large volume of water running off the hill, as well as water from her down spouts and sump pump output, was puddling up in the lawn space and rock beds near their house. 

before water rushing down hill before water pooling picture

Step # 1:  Outdoor Drainage Consultation

The customer reached out to us at KG Landscape and scheduled an outdoor drainage consolation with Kent, our owner and lead designer.  Kent met with the customer at their home to observe the backyard hill drainage issue in person. While there, he collected the site information needed to provide a detailed plan/estimate for a long term solution to the drainage problem.   


Step # 2: A Detailed Proposal

After careful consideration of the drainage problem and the options available to correct the issue, a detailed plan was put together to solve the customer’s exterior drainage problems in a cost effective and dependable way.

Drainage Solution Objective: Collect and control the water running down the hill toward the back of the house before it can cause damage to the plant bed or reach the lawn space below the landscaped bed where it has caused water problems in the past.  Water from the downspouts and sump-pump output will also be collected.  The rock beds must be properly regraded to slope away from the house to prevent water from collecting along the foundation.  All of the water collected will be removed from the problem areas and sent to the street in front.

Below are portions of the proposal used to describe our drainage solutions to the customer:   

Landscape Service Description 

French Drain and Underground Gutter Extensions

Installation of a french drain along the backside of the landscaping at the base of the hill. The french drain will be a 12-18” deep by roughly 18”-24” wide trench lined with filtration fabric with a 4” corrugated pipe in the center. The bottom of the trench will be sloped toward the South end so that water collected will run North to South in the french drain. New edging will be installed around the front and backsides of the french drain and the french drain will be covered with river rock creating a dry creek bed look. 

In the pictures shown below, the blue area represents the location of the french drain and the green lines represent the 4” drainage pipe. Water collected from the french drain will be run through a buried 4” pipe through the landscape bed to the the front of the house along the South side as shown below. (3) catch basins will be installed below the three down spouts on the South side and connect into the 4” pipe running to the front yard. Then, that 4” pipe will connect into a 4” PVC  pipe that will be installed under the driveway before discharging into the street.  Placement of the 4” PVC pipe below the driveway is shown in photo below in Pink.

Additional Drainage Work: 

Removal of existing rock/edging and fabric along the foundation in area marked in yellow below. Install (1.5-2 yds) additional soil to raise soil grade against the foundation along the garage and in front of the deck steps (area shown in yellow below) by approximately 4”-5” and 3-5’ out from the foundation to improve drainage away from the foundation. After new grading work is done, new weed barrier fabric and poly edging will be installed and new 1-1/2” river rock installed. The flagstones in front of the deck steps will be re-used and put back as they were. Also included is the addition of 20 linear feet of french drain shown below in blue using a 4” perforated corrugated pipe and ¾” rock back fill which will “Y” into the primary drainage pipe line that runs toward the front yard. (1) additional drain box (9”x 9”) will also be added to the system. This will collect water from the sump pump output and send that into the primary drainage line. Lastly, any disturbed lawn space in this area will be smoothed back out, seeded with sun/shade seed and covered with straw matting. 

Step # 3: Installation of Drainage Solutions

 Step # 4: Project Completion

Once all of the work described in the proposal had been completed and thoroughly tested by running water through all components of the system, both we and the customer were 100% confident the drainage issues have been solved in a high quality and reliably way.  We’ve kept in touch with the customer and they have had no more puddling and no more erosion issues since this work was completed back in 2018.  The homeowner even provided us a review on our google page describing their experience working with KG Landscape, which we appreciate very much!

Drainage 5 Star Review

We’ve never seen an outdoor drainage issue we couldn’t fix.  Do you have an exterior drainage problem? Call us today to schedule an outdoor drainage consultation at 763-568-7251. You can also submit a quick quote to our website to get in contact with us!