The project just completed work on one of the major reservoirs used by the system.  The Thornton Reservoir is a limestone quarry that can hold 8 billion US gallons (30,280,000 m^2)<p>Here&#x27;s a video of the reservoir taking in 400 million gallons after a heavy rainfall last week:<p><a href="http:&#x2F;&#x2F;www.dnainfo.com&#x2F;chicago&#x2F;20151203&#x2F;south-chicago&#x2F;watch-400-million-gallons-of-stormwater-rush-into-chicagos-grand-canyon" rel="nofollow">http:&#x2F;&#x2F;www.dnainfo.com&#x2F;chicago&#x2F;20151203&#x2F;south-chicago&#x2F;watch-...</a>