Calgary Health Region used SF-Rima permeable pavements for roadways at one of its recently expanded hospitals, a material which eliminates stormwater runoff and helps protect the surrounding watershed, according to a recent case study of the project published in Storm Water Solutions.
Water or snowmelt can infiltrate open joints and filters through various aggregate layers, removing up to 95 percent of the average annual post-development total suspended solids and up to 70 percent of the average annual post-development total phosphorus, according to Storm Water Solutions. That water eventually returns to the local groundwater system.
The hospital had to find a pavement durable enough to withstand harsh winters and adhere to the Calgary’s stormwater management strategy, which was developed to protect the watershed as the city grows.
SF-Rima paving stones developed by SF Concrete Technology allow water to enter through open joints and then drain into the underlying open-graded layers, according to Storm Water Solutions. The water is not retained in the pavement’s surface structure, which helps it avoid damaging freeze-thaw cycles.
The hospital is using regular snow removal equipment on the permeable pavement in the winter months. It’s not using sand or deicing material to avoid clogging the joints and to avoid pollution, according Storm Water Solutions. Gravel material, the same aggregate used in the joints, will be used to provide traction.
Stormwater runoff has created pollution problems along the Mississippi River, prompting farm groups to consider using floating islands built from recycled bottles and seeded with native plants to combat the issue.
Crop fertilizer running into the Mississippi River has led to nitrogen and phosphate-rich water, which eventually reaches the Gulf of Mexico, creating creeping dead zones or hypoxic zones that kill off wide swaths of ocean life. Floating islands could mimic the role wetlands once played and process the nutrients from crop fertilizer before they reach the river.