Thursday, February 02, 2012
Princeton University Stream Restoration--Part 2
previous post. The relatively steep slope allows a nice series of "cross-vein" structures (boulders assembled into the shape of a "v" pointed upstream, designed to focus flow inwards towards the center of the channel.) In the background, through the woods, are Jadwin Gym on the right and the new chemistry building back to the left.
Urban streams tend to get badly eroded over the years by the powerful blasts of flashy runoff coming from hardened surfaces in town. A stream restoration such as this attempts to mend the stream, designing in the right amount of meander, floodplain and well-placed rock formations so that it will resist deformation by the erosive force of all that heavy water coming down the hill.
Assisting in this goal to some extent are some absorbent green roofs and rain gardens installed in new buildings upstream. The tree trunks scattered in the floodplain probably play some role in slowing or redirecting floodwater.