Before we know it, spring will be here and with that can come a fast melt from Minnesota’s winter months. Melting snow and spring showers bring excess water and that may lead to drainage issue in your community association. Having a proper drainage system in place is the best way to prevent damage, and if your association is planning to install or update its current drainage system, it may need to meet stiff requirements from the community and city.
Improper drainage system can leave unsightly standing water, and also creates a safety threat and causes damage to your community’s buildings, surrounding concrete work, and can potentially be a host for mosquitos to lay their eggs. Communities can experience puddling and pooling water when natural environments meant to absorb rainfall are replaced with environments that do not perform the same.
If you live in a community association or a board member at one, it’s important to keep an eye on any greenspace or draining areas to help keep water draining properly and help save the association money. Here are the most common issues a community may experience:
1. Detention basins.
Detention basins are designed to hold water before it can flow into a connecting stormwater system adjacent to the property. The structure as a whole is comprised of an inlet system (often reinforced with a concrete pipe), the basin itself and a discharge outlet (usually a concrete box with openings at the bottom). The outlet structure on the basins tend to be small and can easily clog therefore should be maintained by clearing the openings on a regular basis.
2. Open lawn areas.
As a guideline, lawn and green belt areas should have a 1.5% – 2% slope to help guide water into the stormwater. If the design is made so that the stormwater goes into a low laying drainage channel then this water should dissipate within about 48 hours of heavy intense rainfall. For other areas, standing water should be gone within 24 hours. If you are finding that the water is not dissipating within those parameters, then consider adding additional topsoil to attain the required grade and prevent issues with the system further down the road.
3. Roads and driveways.
For roads, the slope leading to the nearest catch basin or other drainage system should be built with a minimum .5% slope. Driveways are often required to be much steeper, built with a 2% slope. A simple way to know if your community’s roads and drives meet the minimum standard is to pay close attention after a heavy rainfall; any standing water should dissipate within 24 hours. There’s also the “nickel test,” which dictates that no puddle on a roadway be any deeper than a nickel’s thickness. Give it a try after the next heavy rainfall if you suspect drainage issues at your association.
If the detention basins for your roads and driveways are not meeting the standards, a solution to consider is connecting the downspouts from your buildings to an underground piping system that leads to a catch basin. If this is not an option for your community, you can use an infiltration system, which allows water to be absorbed into the ground so long as the soil you’re using complements the system.
If you discover an open area with a drainage problem adding lawn inlets in low areas may help and connecting lawn inlets to your stormwater management system will ensure optimal results. Managing stormwater is an ongoing challenge that requires both vigilance and continued maintenance. The result of this work is a welcoming community that’s safe for your residents and free from the erosion and damage that standing water can cause.
If your board is looking for guidance for updating or replacing a drainage system, your property management company will be able to refer your community to reputable engineers and service companies that can make it happen. For more drainage information and tips to protect your Minnesota community, contact FirstService Residential