Where feasible, large impoundments should be subdivided to increase management options. Different water depths will allow several management strategies, resulting in greater wildlife diversity. Interior levees should be constructed along contours at 6-inch contour intervals. As in waterfowl management, the most important factors involved in shorebird management are proper timing of flooding or drawdown and maintanence or correct water depths. Most shorebirds prefer feeding areas which include shallow water up to three inches deep, exposed bare mudflats and some sites of short, sparse vegetation.
Shorebirds migrate somewhat later in the spring and earlier in the fall than most waterfowl.
The most effective spring management strategy is to maintain higher water levels thoughout the winter, followed by gradual dewatering to expose just the higheset areas of mud during the last week of March or the first week of April. Water levels should then be lowered very gradually at a rate calculated to ensure freshly exposed mud throughout the migration period. Shorebird migrations usually continue through the first week of June. This spring management sequence is quite compatible with waterfowl management since deeper water habits are available during peak duck migrations during late February or March. The shallow areas created by the initial drawdown are also attractive to most puddle ducks, such as northern shovelers and teal.