September ushers in the beginning of fall, and with it comes milder days and cooler nights. This change from summer’s high temperatures affects stormwater systems in a variety of ways–here are just a few.

• Increased oxygen levels. Cool water can hold more dissolved oxygen than warm water. When temperatures decrease in the fall, more oxygen is readily available, which improves the environment for the fish in your pond. You may even be able to shut down your aeration system or fountain for the winter so that you can save money on power without worrying about maintaining a high enough oxygen level because of the natural increase caused by cooler temperatures.
• Fewer and less severe algae blooms. Warm water allows algae to grow quickly and prolifically, while cooler temperatures decrease the speed and density of algae blooms. Unless your pond is extremely shallow, you’ll likely notice a decrease in the amount of algae that grows in your pond during the fall and winter months.
• Plant dormancy. Herbaceous plants, both beneficial and nuisance, will go dormant as the weather cools. The plant matter dies back, turns brown, and starts decaying. It is important to treat nuisance plants with an approved herbicide before they go dormant to deter them from returning full force in the spring.
• Clogging may happen more frequently. The dead matter from dormant plants as well as fallen leaves from surrounding trees can build up quickly and clog the low-flow orifice on your riser. A blocked orifice will allow the water level to rise higher than intended and it could drown shoreline vegetation, so keep an eye out for elevated water levels that may indicate a clog.
• Focus on repairs. While the beneficial vegetation is dormant and there are fewer algae to worry about, you have a good opportunity to focus on structural repairs that the system needs. This may include sediment removal, tree removal, reconstructing rip rap dissipators, patching leaky risers, etc.

Now that fall is here, contact us if you need assistance with any stormwater management services that accompany the change in weather.