![W_logo_color_pos_RGB logo](/images/default-source/brand-portal/logo/w_logo_color_pos_rgb.png?sfvrsn=1a0a3c43_3)
A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. They are also used to control the flow of water for outlets of lakes, ponds, and reservoirs.