Photo Credit: Kathryn Kubicek
Seen here is a broad crested weir in Albion, Michigan. Broad crested weirs serve many purposes including monitoring flow, generating head for power generation, or simply deepening the water way behind themselves to make navigation possible for boats. This weir is of medium size and is currently in an average flow capacity state. During flooding this small drop will turn into a raging torrent that would drown even the strongest swimmers.
Photo Credit: Karl Jansen
Pictured here is a small weir. A weir is simply a wall or some sort of barrier placed within an open channel which restricts the movement of water as it flows downstream. Weirs are used to change the flow characteristics in a stream or river and manage the flow rate within the channel. In this way, engineers can use devices such as the weir to prevent flooding and sustain the safety of the public.
Photo Credit: Alex Mead
The Sixth Street Dam, or more properly the Sixth Street Broad Crested Weir, is located near downtown Grand Rapids, MI on the Grand River. It was constructed originally to power furniture mills but currently has no direct application. Typically, there is a six to eight foot vertical drop from crest to the downstream water surface but in flood conditions this can be reduced to only two or three. The Sixth Steet Dam is also fitted with a fish ladder to allow migratory fish, like salmon and steelhead, to pass and continue up stream.