Abstract: The device herein disclosed and described provides a water collection system that separates the initial flush of rainwater, which contains higher concentrations of undesirable contaminants from later received rainwater having lower concentrations of contaminants to be stored for later use or to be discharged directly to receiving bodies of water. The device contains a cistern for treating first flush rainwater, a basin for receiving water in fluid connection with the cistern and a water storage tank, a water diversion channel that diverts first flush rain water to the cistern and additional rainwater to a water storage tank, a floatation device on a connecting rod affixed to the diversion channel that acts to operate the diversion channel when the water in the cistern achieves a desired height by diverting the additional water received to the water storage tank.

Abstract: The device herein disclosed and described provides a water collection system that separates the initial flush of rainwater, which contains higher concentrations of undesirable contaminants from later received rainwater having lower concentrations of contaminants to be stored for later use or to be discharged directly to receiving bodies of water. The device contains a cistern for treating first flush rainwater, a basin for receiving water in fluid connection with the cistern and a water storage tank, a water diversion channel that diverts first flush rain water to the cistern and additional rainwater to a water storage tank, a floatation device on a connecting rod affixed to the diversion channel that acts to operate the diversion channel when the water in the cistern achieves a desired height by diverting the additional water received to the water storage tank.