Contributed by Matt Verdirame
Now that summer is fast approaching we should all be aware of methods we as homeowners could use to help control algae in the lake by reducing the nutrient amounts. These are eight recommended methods that we should all endeavor to follow to help reduce runoff into the lake.
These methods are:
1. Riparian buffers of native trees and plantings which provide shade as well as reducing erosion and filtering runoff.
2. Rain harvesting with the use of roof fed rain barrels to water gardens and plants.
3. Infiltration rain gardens which allow more water to get into the ground as opposed to impervious surfaces that increase runoff into the lake.
4. Picking up after the pets and disposing of waste properly.
5. Not feeding waterfowl.
6. Composting garden materials away from the lake drainage.
7. The use of limestone in the watershed to increase ph.
8. Testing the soil before fertilizer and pesticide use that enables you to put on only what is needed which not only aids growth but will also save money.
I would like to expand on fertilizer application as this is an area often incorrectly applied by both homeowners and professionals. Excessive or improper fertilization, when combined with storm water runoff, will carry these surplus nutrients away from the target areas and deposit them into the lake which will lead to further phosphorus buildup (Eutrophication). Eutrophication is the unwanted enrichment of an aquatic ecosystem with excessive nutrients, mainly nitrogen and phosphorus.
Prior to applying fertilizer, several questions should be asked. First, has soil testing been done to determine the exact amounts of N and P required for your site? A soil test will determine which nutrients are already at sufficient levels and how many nutrients are actually needed. Research has shown that lighter more frequent applications of fertilizer is better for the turf and reduces the runoff of fertilizers.
It is also important to know what type of fertilizer works best for your needs? Most soils in our region already have an abundance of phosphorus and most lawns will not require additional phosphorus. Phosphorus generally will not be available for uptake by turf grass; therefore the excessive and careless application of phosphorus can lead to high levels of phosphorus in the runoff into the lake.
Finally, are there impervious areas on the site which can concentrate the fertilizer and allow it to be carried away in storm runoff? Make sure fertilizer is swept off roads, driveways, and walks back into the turf to reduce the chance of it running off into the lake. An unfertilized buffer of 10 to 15 feet should be left around all swales or runoff streams to reduce the chance the fertilizers being carried directly to the lake.
The old adage states that 5 pounds of phosphorus can equate to 500 pounds of wet algae. Every one of us can make a significant difference and play a necessary role in protecting our lake. Simply by allowing grass to grow higher in vital areas such as runoffs, swales, and areas adjacent to the lake can help control runoff into the lake.
You may have noticed that in many community areas the grass is being allowed to grow long in the runoffs and also by some areas at lake edge. We are doing this to reduce runoff as these longer grass areas will help catch sediments which contain much of the phosphorus. At the end of the growing season these areas are to be cut down and then the clippings composted away from the lake.
Along with this we have introduced some floating islands onto the lake. These islands contain plants which take up nutrients and grow rapidly. At the end of the growing season these plants will be removed from the islands and composed away from the lake. In addition we are planting pickerel weed and cattails around the lake and in runs, these native plants will not grow indiscriminately as they too soak up nutrients. At the end of the growing season these plants will also be cut off and composted away from the lake.