The USGS is the principal source of data on river depth and flow. According to the U.S. Geological Survey, stream levels for some Indiana rivers have already exceeded highs recorded during the 1913 flood , the largest flood ever documented across much of the state and a break in the persistent rains is expected, peak flows along some major rivers are yet to come. Because additional heavy rainfall expected around Indianapolis would further exacerbate the situation along the White River, the USGS Indiana District would dispatch field crews to document the floodwater levels in that area. Much of these data are gathered at gauging stations throughout the U.S. and transmitted by satellites to the web in real time to users such as the National Weather Service, which relies on the information to determine when it should issue flood warnings, and to emergency managers. Some of the USGS gauging stations provide information needed to design dams, bridges, and water- and waste-water-treatment plants. Currently, the USGS Indiana data network includes 170 stream-flow gauging stations. The network is funded in a cooperative program of federal, state, and local agencies. USGS stream-flow measurement teams use high tech Doppler sonar flow meters called acoustic Doppler current profilers to make accurate stream-flow measurements very quickly. The ADCPS are deployed from unmanned tethered boats and transmit data to hydrologists using radio modems on shore. The USGS serves the nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect the quality of life.