In 2016, a study by the USGS in Madison, Wisconsin revealed the removal of fallen leaves can reduce phosphorus concentrations found in stormwater by 80%. Further, it was found leaf litter and other fall organic debris contributed 56% of the annual total phosphorus load in urban stormwater. This was reduced to 16% when streets were cleared of leaves before rain events.
Leaves – What is the big deal?
In Iowa, the beauty of fall and colorful fall leaves is something many of us look forward to. However, in our urban environments, fall leaves can lead to a huge annual water quality problem. Leaves represent one of that largest sources of urban phosphorus pollution. As leaves break down they release phosphorus. When left in the street, phosphorus from the leaves is transported by stormwater which travels through storm drains that lead directly to our streams, rivers, and lakes.
But leaves are natural….Right?
In a natural environment without streets, parking lots, and storm drains, leaves fall onto the ground and decompose releasing phosphorus into the soil. In an urban environment, majority of the landscape is covered in streets, parking lots, and other impervious surfaces. When leaves are left on streets, phosphorus is easily washed into storm drains and our streams and lakes instead of soaking into soil.
The effects of phosphorus
Excess phosphorus can lead to major water quality problems. Excess phosphorus contributes nutrients to our water bodies that can lead to excessive plant and algae growth (eutrophication) and eventually lead to a depletion of oxygen in the water (hypoxia) leading to fish kills.
Did you know it only takes one pound of phosphorus to produce 500 pounds of algae?
Phosphorus in Easter Lake
Before the start of lake restoration, phosphorus loading into Easter Lake equaled approximately 4,250 pounds per year. Within the Easter Lake Water Quality Management Plan, a major project goal is to reduce phosphorus loading into the lake by 40% or 1,710 pounds per year. Partners of the Easter Lake Watershed Project have taken on measures to reduce phosphorus in Easter Lake. These measures include lake dredging, shoreline stabilization, stream bank stabilization, and the installation of conservation practices throughout the watershed. These improvements will bring benefits to Easter Lake for years to come. However, to reach phosphorus reduction goals for Easter Lake now and into the future, we need your help.
What you can do
If you live in the Easter Lake Watershed, all the stormwater running off your house, streets, parking lots flows into storm drains that lead directly to Easter Lake. So, each action you take to reduce pollutants, such as phosphorus, will help Easter Lake will be healthier, cleaner, a better fishery and recreational resource for everyone.
Keep leaves off the street
One of the most impactful things you can do is to keep leaves off the street. Be mindful about where and when you rake your leaves for collection. When you are raking your own yard, help keep streets clean and storm drains free of debris by raking and picking up leaves a few feet into the street in front of your home.
Keep leaves off driveways, sidewalks, and other impervious surfaces
Avoid the easy transport of leaves and phosphorus into storm drains by removing leaves off of impervious surfaces.
Compost your leaves
Rake your leaves and other yard waste and compost it to use as fertilizer for your garden in the spring. Don’t have a place for compost? Contact your local waste management and check their policies for yard waste pick up. In Des Moines, Iowa the Metro Waste Authority can collect your yard waste through their “Compost It!” program.
Mulch your leaves
If your yard is flat, mow leaves on your yard and leave them in place. The leaves will provide nutrients to your lawn to keep it healthy. Mowed leaves can also serve as a mulch around plantings.
Clean water starts with you