Stream Meanders
Meanders in the stream channel add to the distance that water must travel from upstream to downstream.
Consider a basin with meandering stream channels. If all of the meanders were straightened out, the distance that the water travels through the streams would decrease. This reduces the time it takes water to travel to the basin outlet. It also decreases the time over which water may infiltrate the ground through the bottom of the stream channel.
Meanders increase the travel time of runoff through the basin, and may reduce the overall runoff volume.
Additional Resources:
For more information on how landscape features such as river meanders are formed, consult the Fluvial Geomorphology Module from State University of New York College of Environmental Science and Forestry (SUNY ESF) http://www.fgmorph.com