The Heinz Center's State of the Nation's Ecosystems
ecosystem: Freshwater
indicator Name: Changing Stream Flows: Alteration of Key Flow Characteristics
page # in printed report: 142
location on page: upper
data source: U.S. Geological Survey; analysis by Colorado State University. Coverage: lower 48 states.
notes: please see technical notes for further details on accessing these data from their original source; this data table comes from a specific graphic in The State of the Nation's Ecosystems report (www.heinzctr.org/ecosystems)

units: % of gauged streams/rivers
  Major Moderate Minimal
1970s 55.1 35.4 9.5
1980s 56.9 33.5 9.7
1990s 60.8 30 9.2