If the extraordinary ResilienCity comes to pass, Boston in 2035 will be a very green and exciting place indeed. Far surpassing Masdar City and other eco-dreams, this map-lab Living City Design Competition entry not only restores Boston's former ecological glory, but also ensures an almost excessively healthy and safe environment for its future residents. In addition to generating four times the amount of energy it will actually need, the designers propose to convert an underground bus tunnel into a giant, 20 million gallon water cistern and outfit every home with a list of "ingredients" that depicts its sustainability!
20 million gallons is not a lot. An inch of rain over a hundred acres is 2.7 million gallons. I doubt the containment potential of the cistern. Better off simply having rain barrels at individual houses. That ensures private rights to the water that falls on the persons property. This isn’t a park pond so people will tend to ignore it. What potential is there for mosquito breeding grounds in collected dirty water.
For reference: A 20M GAL capacity would supply over 36,000 US residents (at 550 GAL/Person – highest in the world in use). That a figure in addition to individual on-site water-saving & storage strategies. As far as mosquito breeding grounds – that is not how the system would work (a stagnant and standing vessel) – its a municipal water “reservoir” and tidal rise holding tank/desalinization facility (using the tidal energy as the power source for the processing)