It is rare for one plan to be the best by every measure, so plan selection is not an automatic product plan evaluation.  To select the best plan,  study teams must balance the measured and unmeasured economic, financial, political, environmental and social consequences of each of the alternatives in a process that is open, logical, and consistent.

In some cases, the plan selection process is defined by regulation.  For example, planners examining the feasibility of Federal flood damage reduction or navigation projects must recommend the plan that meets environmental requirements and maximizes net National Economic Development benefits (a waiver to this rule can be granted, but the "NED Plan" is the norm).  But in many water conflicts, plan selection must be approved by multiple decision makers, each with their own decision criteria.  In large capital improvement projects, plan approval may have to come from several agencies and governments. For example, a Federal water project might be recommended at a Corps district after a state government has signed a Project Cooperation Agreement, then reviewed at several levels within the Corps and OMB, then debated in the U.S. Congress.  In other cases, especially cases involving a change in the operation of existing water projects, plan approval may be come from the heads of the agencies that developed the plan recommendation at the staff level.