Blooms of green disturb South Suburban ponds

Have you seen the green growth in the ponds in South Suburban’s parks? Are you wondering what’s going on?

The dog days of summer are upon us and temperatures have really heated up. Even the evenings stay warm. These high temperatures coupled with the low rainfall and reduced water levels cause the green algae in the ponds to multiply. Although a certain amount of algae is healthy for bodies of water, the rapid growth of algae depletes the oxygen in the water. When the oxygen in the water becomes highly depleted and the algae dies changing color, it gives off the odor of sulfur springs.

So what can we do to reduce the problem? There are three things that can help dissipate the difficulties associated with algae growth, adding fresh water and/or oxygen or treating the problem with algaecide. Introducing a large quantity of fresh water to the pond can improve the situation and can be accomplished early in the season. However, late in the summer water levels in the creeks and rivers that feed South Suburban’s ponds are also low. Ketring Lake, in Littleton, is replenished by the High Line Canal, which has not had water flowing in it since four days in early July. Since this July replenishment, the water level of Ketring Lake has dropped more than one foot. Unfortunately, without sufficient flows in the feeder creeks and rivers adding water to these algae laden ponds is not an option.

The second and more plausible choice is to add oxygen to the pond. This can be accomplished by utilizing water pumps that circulate the water within the pond adding oxygen. Three water pumps are being used in Ketring Lake to move the water increasing the flow and oxygen levels.

The third option of algaecide treatment can be considered. According to water quality and fishery consultants, this treatment could further reduce water oxygen levels. This advanced reduction could threaten the health of the lake and the many fish that make it home.

South Suburban’s pond algae bloom is an occurrence that periodically repeats when the conditions of late summer high temperatures and low water levels bump up against each other. Although the look and smell can be unpleasant, these algae blooms pose no significant risk for humans, pets or wildlife. However, like any non-potable water, the water in South Suburban lakes, ponds, creeks and rivers should not be consumed. As summer turns to fall and daytime and nighttime temperatures cool, the green algae blooms in South Suburban’s ponds will naturally disperse.