About those streamgaging costs......

In fiscal year 2001, the cost of operation of a streamgage in our District increased by 9 percent; a source of consternation both internally and among our cooperators. Over the previous 7 years, costs had risen only at the rate of inflation. The unusual 2001 increase resulted from a restructuring of the U.S. Geological Survey (USGS) budget that reduced the net funds available for District operations.

Over the past several decades, a number of changes have affected streamgaging costs. Advances in sensor technology, particularly pressure transducers, have eliminated the need for stilling wells and manometers, thus greatly reducing gage- construction costs. Electronic data storage, satellite telemetry and automated data processing have greatly accelerated the processing of records and dissemination of data. Yet, one of the most expensive parts of the operation, stream-discharge measurement, has remained largely unchanged. This operation is manpower intensive, and associated costs have increased greatly for a number of reasons.

Safety requirements for streamgaging operations have increased significantly. Today, every gaging site requires a site-specific Job Hazard Analysis that identifies a multitude of potential hazards and prescribes safety measures to address them. Cableway systems for measurements at high flows are now subject to much stricter design and testing standards, requiring that many systems be rebuilt over the past decade. For sites without cableways, where high-water measurements must be made from bridges, traffic-control plans must be developed and implemented. Discharge measurements from watercraft and on ice-covered streams have likewise become more demanding. Stilling wells in older gaging stations, that require periodic flushing and maintenance of intakes, are now classified as confined space, with associated Occupational Safety & Health Administration (OSHA) requirements. Many streamgaging operations now require a two-person team where a single individual was involved in the past. At the same time, the knowledge and skills required of hydrologic technicians has greatly increased and include proficiency in electronics and computer technology. In FY-2000, the long-overdue increase in the full-performance grade level of USGS Hydrologic Technicians was finally approved. The need for these skills must be reflected in gaging costs.

On the benefits side, our cooperators and the public are getting much more for their gaging dollar today than ever before. In particular, the timeliness and availability of stream-flow data has increased tremendously, whereas the amount of lost record has declined sharply. Over the past 6 years, the District has made a concerted effort to convert the network to near-real-time reporting. In 1995, about 40 percent of the network had real-time reporting to a very limited number of users. By the end of 2001, essentially 100 percent of the network (more than 90 stations) will have real-time reporting on the World-wide Web. In addition, an increasing number of stations are being equipped to transmit rainfall and water-quality parameters.

The USGS has just released NWISweb (National Water Information System on the World-Wide Web). This system, illustrated on page 9, will significantly enhance the capability of all users to view and download USGS water data, including ground-water and water-quality information. NWISweb will allow users to access both real-time and historical data and to develop customized graphical and tabular outputs. Users will be able to obtain real-time data for the past 31 days, and obtain provisional mean-daily flow values back to the beginning of the water year (no more gaps in data availability between real-time and historical records!). Peak-flow data, discharge-measurement data, and detailed site information will also be available on-line.

In conclusion, there is reason to believe that emerging technology will eventually reduce the costs of streamflow measurement. Last year, the District purchased its first Acoustic Doppler Current Profiler (ADCP) which employs sophisticated sensor and digital technology to accurately measure discharge on larger streams in a matter of minutes, compared with current-meter measurements that would have taken hours. New prototypes are being developed and tested that will permit this technology to be employed with hand-held instruments on smaller, shallower streams. USGS' ultimate goal is to `get the streamgager out of the stream' entirely. An internal program called `HYDR0 21' has been established to assess and incorporate new technologies within the hydrologic-data network. In addition to improved transducer and acoustic instrumentation, HYDRO 21 is investigating a variety of non-contact instruments, such as radar, to measure velocities, stages, and river cross-section geometry. The future may not be far off where streamflow measurements will be made entirely by remote sensing devices.

 

--Brian R. Mrazik

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