Let it Rain - Managing Stormwater
We wanted a small, simple cottage down by the lake. Turns out, it was anything but simple.
Just getting the driveway down the hill to the building site was a challenge. Properly managing stormwater was essential to ensure the hill and driveway would be stable in heavy rains. The main goal was to keep water on top of the hill with plenty of basins to hold the rainwater. The water could not run down the slopes or driveway because it would wash out the sandy soils. The second priority was to keep water out of the lake with thoughtful roof design, basins, and a shoreline buffer.
We interviewed multiple excavators and had experts from CWSWCD, MPCA, and the U of M extension office come out to the site for advice. CWSWCD created a stormwater management plan and provided guidance for seeding the slopes. Berms and swales made from reserved topsoil now direct all the water from the pre-existing shed roof into stormwater basins.
Four years later, Native flowers, grasses, and apple trees soak up the stormwater in the swales and basins.
The top of the driveway is sloped to dump water into large basins on the right. A vegetable garden was planted in one of the basins.
Asphalt curbs on both sides of the lower part of the driveway direct the water into a large stormwater basin at the bottom. A berm ensures the water doesn't drain into the lake. The curbs also prevent wash outs on the steep slope next to the driveway.
The steep slopes needed immediate protection and vegetation. The excavator saved topsoil and put down a good layer to help seeds get started. Just before snowfall, the slopes were generously seeded with Minnesota Native Landscapes “Steep Slope Mix” and a cover crop. Curlex blankets (purchased at BrockWhite) were staked in place to stop erosion and help the seeds germinate in the spring.
Native prairie plants thriving on the same hill, 4 years later! Monarda (Bee Balm), Yarrow, and Brown Eye Susan attract birds, bees, and butterflies. The drainfield was seeded with a native Septic Mound seed mix provided by CWSWCD.
The house roof was designed to drain water away from the lake and into a swale and basin behind the house.
All of the careful planning paid off. The site performed very well in a 10-inch rain event.
The lakeshore was designed to minimize maintenance and reduce runnoff into the lake.
The lawn around the home is seeded with a "Cabin Grass/No Mow Grass Seed Mix" from Landsburg's Nursery. The roots grow deeper to absorb more water and mowing is infrequent.
The shoreline was left natural as possible while still keeping a view. Invasive reed canary grass was removed and the site was re-seeded with a shoreline seed mix.
In 2019, we were finally able to move into that simple little cottage down by the lake.
