Rain Garden Excavation at Three Rivers Community College

Yesterday was excavation day at Three Rivers Community College. Jenna Messier, Mike Deitz, the contractor Jim Benjamin Sr., his son, Jim Jr., and I were there all day to prep the site for the June 6th planting. Professor Diba Khan-Bureau and a few of her students were on site in the afternoon to watch and document the project.

Mike overseeing the dig!

At TRCC, we had to make a curb cut, dig the basin, install an overflow pipe, and create a sediment barrier. The goal of this project is to divert storm water from the adjacent parking into the rain garden and away from the storm drain.

Here are some highlights from yesterday:

The first step in the excavation process was removing soil to create the depression where storm water will be stored for a short period of time before draining into the ground. For this specific site, we excavated about 14 inches below grade, since we had electrical conduit at 18 inches below grade.

Jim Jr. making the curb cut

Secondly, we made the curb cut. This particular cut was strategically placed next to the storm drain so that all of the storm water from the adjacent parking lot would enter the garden before it reaches the drain.

Mike again! Installing the platform

We then built a platform at the entrance of the curb cut and installed cement patio blocks to catch sediment from the parking lot before it can enter the garden. This will allow for easy clean-up in Spring, by taking a flat shovel and scooping out the sand from the winter maintenance.

Drainage pipe!

After installing the platform, we laid an over-flow pipe at the base of the garden that will drain excess water into an adjacent wooded area in the event of a large rain storm that will discharge more water than the garden can handle.







Lastly, we filled in the basin with beautiful soil making sure to keep a slight depression that will temporarily store storm water!

The rain garden is ready for planting on June 6th!

Jenna and Mike discussing some last-minute details

We will be putting together a full step-by-step PDF which will show the entire process and can be used by anyone for teaching or practical purposes.