With 520-miles of waterfront and four-out-of-five boroughs islands, New York City is truly a water city. Everywhere you go, there are tunnels and bridges delivering you over water, to such a degree some have dubbed the waterways that encircle New York City "the sixth borough." We spent several months filming both the natural water landscape and the activists trying to improve its health. From Brooklyn's Newtown Creek to Queens' Flush Meadow, waterways once thought ruined forever by industrial and man made pollution are making a comeback. From the Billion Oyster Project to Dragon Boat races, from the Gowanus Canal to the Harlem River, there is brand new activity on all of the waterways that surround NYC, making this the cornerstone of our new 'Hope on the Hudson' series.