The following types of data are often useful:
Streamflow gage records and their locations
Estimates of streamflow for ungaged locations calculated using gage records, drainage area or other parameters
Reservoir storage levels, volume-elevation relationships, net monthly evaporation rates, operating rules for fish and wildlife, recreation, hydropower, navigation, water supply and other conservation purposes
Groundwater recharge rates, gains from and losses to rivers
Instream flow requirements for recreation, water quality, fish and wildlife, navigation, other conservation purposes, and any downstream obligations
Transmission link capacities and losses
Wastewater and effluent routing
Costs of delivered water