RAINWATER HARVESTING SYSTEM

Better For The Environment And The Community

Because water is a precious, life-supporting resource, the Conservancy strives to enhance our economic, ecological and social impact through thoughtful water usage. In our view, the McMullen Family Conservation Center is part of a dynamic watershed. By integrating efficiency with respect for water, the facility also uses a system designed to function like one.

The majority of water usage in most buildings is associated with flushing toilets. By harvesting rainwater for this purpose and not using treated municipal water, more of this precious resource is available for drinking and other essential needs throughout the community.

Rather than using stormwater sewers to handle excess rainwater, the bioswales near the Conservation Center mimic the natural function of wetlands. They purify water naturally and recharge groundwater before it reaches East Grand Traverse Bay, the source of Traverse City’s drinking water.

How The System Works

During rainfall, the first surge of water that enters this system carries the most contaminants, which may include dirt, pollen and other debris that accumulates between rain events.

The first flush diverter prevents these contaminants from entering the Conservation Center’s water supply. When it rains, the “first flush” of rainwater flows from the roof to the first flush diverter to separate the debris. This rainwater is temporarily stored in the diverter and slowly released into the bioswale to be further filtered naturally. Once empty, the diverter is ready to filter water from the next rainfall.

When the diverter becomes full, harvested rainwater bypasses it and flows to the pre-filter before being stored in the basement cistern (see flow arrows). The pre-filter protects the cistern from collecting leaves and debris.

Water in the cistern is pumped through a series of filters before being disinfected by ultraviolet light and used to flush toilets throughout the facility. If the cistern is sufficiently full, the diverter valve closes access to it and directs water into the bioswale, where it is naturally filtered before recharging the groundwater.

When full, water from the roof bypasses the diverter to the pre-filter and cistern (see flow arrows).