Q. Our neighborhood association is spending a great deal of money each year to keep our retention pond weed-free. Are there any alternatives to these expensive treatments?
A. Yes and no. It is important to use licensed professionals who are bonded and insured for pond management issues in an association setting. I know that sometimes organizations have their own people treat the pond. This raises all sorts of liability issues. Also remember that if someone is paid to apply pesticides, that person needs to be licensed.
Part of the issue with neighborhood association retention ponds is that many are just not deep enough (18 feet in depth). Shallow ponds just invite weeds and algae because sunlight can penetrate into the water all the way to the bottom – encouraging algae and aquatic weed growth. In addition many ponds were constructed with steep slopes leading to the ponds – encouraging erosion and silt buildup which decreases water quality.
Another issue is unrealistic expectations. A natural pond has vegetation in and around the pond that will help keep the water clean. Many urban dwellers want a pond devoid of vegetation because it is somehow perceived to be cleaner. Any vegetation is perceived to be a weed. Many associations want a pond devoid of vegetation and also want fish. Healthy fish need cover to flourish.
Finally, many homeowners associations want a lush beautiful lawn that extends right to the pond edge. They often can be unwilling to change fertilization habits to maintain the lawn. This can lead to algae problems from nutrient leaching into the pond, and encourage Canada geese to visit because the geese love the tender new shoots of young grass.
In this new age of sustainability, neighborhood associations might need to re-evaluate their expectations and behaviors regarding pond appearance and management.
At the very least, low or no phosphorus slow release lawn fertilizers need to be used by all homeowners in a neighborhood in the spring. This practice alone will reduce nutrient run-off, and save your association money. Do not apply any fertilizer within 20 feet of the waters edge.
Think about establishing some desired aquatic vegetation in and around the pond. This vegetation will also filter, capture, and clean the water entering the pond. I see large drains and culverts emptying nutrients and other toxic materials from all the lawns and driveways directly into the pond. Establish buffer vegetation around the drains to slow and clean the water. Establish an Eco-Grass around the pond edge. These fescue blends need less mowing and less fertilizer and their deeper root systems will also help clean the pond.
A bubbler system can also help. Most bubblers work by circulating water over barrels of lava rock. This keeps the water moving (preventing weed growth) and also will help to clean the water naturally.
To save money and maintain cleaner water in a more environmentally friendly fashion, associations need to re-evaluate management practices and consider a more sustainable approach.