National Streamflow Information Program: Implementation Status Report

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… from the National Streamflow Information Program

This Fact Sheet is one in a series that highlights information or recent research findings from the USGS National Streamflow Information Program (NSIP). The investigations and scientific results reported in this series require a nationally consistent streamgaging network with stable long-term monitoring sites and a rigorous program of data collection, quality assurance, management, archiving, and synthesis. NSIP produces multipurpose, unbiased surface-water information that is readily accessible to all. Introduction

The U.S. Geological Survey (USGS) operates and maintains a nationwide network of about 7,600 streamgages designed to provide and interpret long-term, accurate, and unbiased streamflow information to meet the multiple needs of many diverse national, regional, state, and local users. The National Streamflow Information Program (NSIP) was initiated in 2003 in response to Congressional and stakeholder concerns about (1) the decrease in the number of operating streamgages, including a disproportionate loss of streamgages with a long period of record; (2) the inability of the USGS to continue operating high-priority streamgages in an environment of reduced funding through partnerships; and (3) the increasing demand for streamflow information due to emerging resource-management issues and new data-delivery capabilities. The NSIP’s mission is to provide the streamflow information and understanding required to meet national, regional, state, and local needs.

Most of the existing streamgages are funded through partnerships with more than 850 other Federal, state, tribal, and local agencies. Currently, about 90 percent of the streamgages send data to the World Wide Web in near-real time (some information is transmitted within 15 minutes, whereas some lags by about 4 hours). The streamflow information collected at USGS streamgages is used for many purposes:

In water-resource appraisals and allocations—to determine how much water is available and how it is being allocated;
To provide streamflow information required by interstate agreements, compacts, and court decrees;
For engineering design of reservoirs, bridges, roads, culverts, and treatment plants;
For the operation of reservoirs, the operation of locks and dams for navigation purposes, and power production;
To identify changes in streamflow resulting from changes in land use, water use, and climate;
For streamflow forecasting, flood planning, and flood forecasting;
To support water-quality programs by allowing determination of constituent loads and fluxes; and
For characterizing and evaluating instream conditions for habitat assessments, instream-flow requirements, and recreation.

National Streamflow Information Program: Implementation Status Report

Streamgage-Network Instability

The number of streamgages operated by the USGS over the past 40 years (fig. 1) has varied from a high of about 8,300 in 1970 to a low of about 6,800 in 1998. Over this 40-year period, the number of streamgages has decreased by more than 660 even though the need for streamflow information has increased due to increasing population, required habitat assessments, new water-quality requirements such as total maximum daily loads, and the need to understand the effects of climate change. The instability of the streamgage network over the past 40 years can also be illustrated by the loss of streamgages that had at least 30 years of information when they were discontinued (fig. 2). Data from long-record streamgages are critical for identifying changes in the amount and timing of streamflow caused by changes in land use, water use, and climate.

Much of the streamgage-network instability is directly attributable to variations in funding. For example, funding sources for the USGS streamgage network in fiscal year 2009 are shown in figure 3. The USGS has direct control of only about 15 percent of the funds required to operate and maintain the network (the NSIP funds). The USGS contributes another 17 percent of the streamgage-network funding through the USGS Cooperative Water Program (CWP), which requires at least a 50-percent match from the cooperating partner for the USGS to invest the CWP funds for streamgaging. Funds from state and local agencies for streamgaging are not being matched dollar for dollar by the USGS CWP; those agencies are currently providing about $2.6 for every $1 provided by the CWP. Consequently, when partner funding is reduced, the water community often loses streamgages because there is inadequate funding to maintain them. As a result, the network’s ability to meet long-term Federal needs for streamflow information is uncertain.

Number of discontinued U.S. Geological Survey streamgages with 30 or more years of record, 1970–2009.

Figure 2. Number of discontinued U.S. Geological Survey streamgages with 30 or more years of record, 1970–2009.

To respond to this issue, the USGS developed a plan for the National Streamflow Information Program (U.S. Geological Survey, 1999). This fact sheet briefly describes the current status of the NSIP and the progress that has been made in implementing the five goals outlined in the NSIP plan. Because the needs for and uses of streamflow information are ever-changing and technology is constantly advancing, the NSIP plan must be modified over time to ensure its continued usefulness and relevance.

The five goals of the program, the objectives associated with each goal, and the implementation status of each objective are described below.

Goal 1: Stable Streamgage Network

Currently NSIP’s priority goal is to establish a stable “backbone” streamgage network to fulfill the five Federal needs for streamflow information (described in the box on the next page). A total of 4,756 streamgage locations strategically distributed across the country have been identified to meet these needs; more than 900 of these streamgages will meet more than one of the Federal needs. The NSIP’s plan is for the total operation and maintenance costs of this core set of permanent, continuously operated streamgages to be provided by the USGS. This stable Federal funding will ensure that real-time delivery of critical streamflow information is uncompromised by fluctuating funding. The plan is also for all streamgages to be modernized and hardened to withstand both floods and extreme weather so the data are reliably available when they are most needed.

Objective 1

Add new (or reactivate discontinued) streamgages at specific identified critical locations to establish the complete federally funded “backbone” network of 4,756 streamgages. As of 2001, 484 new streamgages and 864 reactivated streamgages were needed to complete the network as designed.

Status. Currently, 3,032 (64 percent) of the 4,756 NSIP “backbone” streamgages are operated year round by the USGS. An additional 323 (5 percent) are operated by the USGS for less than a full year (partial record), and 186 (4 percent) are operated by a non-USGS agency. Currently (2010), 323 new and 877 reactivated streamgages are needed to complete the network as designed, indicating that 67 additional streamgages have been lost from the NSIP network since 2001. The priority to date for the limited funds available has been to sustain the operation and maintenance

Critical Federal Needs for Streamflow Information

Five critical Federal needs for streamflow information that would be met by the core set of 4,744 USGSfunded streamgages in NSIP have been identified:

Interstate and International Waters—Interstate compacts, court decrees, and international treaties mandate long-term, accurate, and unbiased streamgaging by the USGS at State-line crossings, compact points, and international boundaries.
Streamflow Forecasts— Real-time stage and discharge data are required to support flood and other streamflow forecasting by the National Weather Service and other Federal agencies across the country.
River Basin Outflows— Resource managers need to account for the contribution of water from each of the Nation’s 350 major river basins to the next downstream basin or other receiving water body (estuary, Great Lake, or ocean).
Sentinel Watersheds— A network of streamgages is needed to document and evaluate streamflow characteristics in 800 watersheds across the country that are relatively unaffected by flow regulation or diversion and typify major ecoregions and river basins to determine effects of changes in land use, water use, and climate.
Water Quality—Streamgaging stations are needed to provide the stream-discharge information in support of the three USGS national water-quality networks. Through these three networks, the USGS monitors and documents water quality in the Nation’s streams, from the largest river basins to the smallest watersheds.

of existing streamgages threatened with discontinuation rather than to fund new or reactivated streamgages.

Objective 2

Upgrade equipment at existing streamgages that do not currently have the capability to transmit data in real time, and upgrade to high data rate (HDR) transmitters at all streamgages. The expected outcomes are that additional streamgages will deliver real-time information to the World Wide Web at shorter time intervals, and that compliance with the directive that all transmitters to the Geostationary Operational Environmental Satellite (GOES) be equipped with HDR transmitters by 2013 will be achieved.

Status. The USGS streamgage network currently (2009) is at about 90-percent real-time capability; nearly all of those streamgages are equipped with the new HDR transmitters.

Objective 3

Implement the NSIP network of federally funded streamgages as authorized in Public Law 111.11, for the operation and maintenance of a stable network of 4,756 streamgages. The NSIP network of federally funded streamgages to meet national needs would be in conjunction with partner-funded streamgages to meet additional state and local needs and make up the National Streamgage Network. The expected outcome is that NSIP funding for critical streamgages currently operated under the CWP or with other Federal agency funds would be secure and would ensure the uninterrupted delivery of critical streamflow information to meet Federal needs. Moreover, CWP and associated state and local funds released as a result of the NSIP funding of streamgages would be available to support additional streamgages to meet local needs and to supplement the core set of federally funded streamgages.

A typical U.S. Geological Survey streamgage, Little Walker River near Bridgeport, Nevada.

A typical U.S. Geological Survey streamgage, Little Walker River near Bridgeport, Nevada. 3

Funding sources for the U.S. Geological Survey streamgaging network, 2009. (Values are in millions of dollars; total funding $146.3 million; OFA, other Federal agencies; NSIP, Nati

Figure 3. Funding sources for the U.S. Geological Survey streamgaging network, 2009. (Values are in millions of dollars; total funding $146.3 million; OFA, other Federal agencies; NSIP, National Streamflow Information Program; CWP, Cooperative Water Program)

Status. Currently, 3,032 (64 percent) of the 4,756 NSIP “backbone” streamgages are operated year round by the USGS. NSIP currently fully funds only about 378 (12 percent) of these streamgages; NSIP shares costs with partners for another 965 streamgages (32 percent). The remaining 1,689 existing NSIP streamgages are completely funded by other Federal, State, tribal, and local agencies and the CWP. Nearly 1,200 additional streamgages, which will also require Federal NSIP funds to operate and maintain, remain to be added to complete the planned network.

Objective 4

Flood-harden streamgages at National Weather Service forecast locations to the 200-year-flood level to ensure that they continue to provide critical data during floods. The expected outcome is that approximately 3,600 streamgages used for forecasts would be flood hardened under full NSIP implementation.

Status. NSIP resources have not been sufficient to meet this objective to date, as all available resources have been invested in higher priority NSIP objectives. However, approximately 140 NSIP streamgages were flood-hardened with supplemental funding obtained as a result of Hurricanes Katrina and Rita.

Objective 5

Federally fund infrastructure costs of the entire national streamgage network. Supporting additional streamgages to meet state and local needs, funded through the CWP, adds little to overall infrastructure costs. These incremental added costs include those for activities such as national database development and maintenance, local database administration and project oversight costs, and the USGS Office of Surface Water, which provides technical guidance and oversight for all USGS surface-water activities at the national level.

Status. USGS Water Science Centers (WSCs) have been allowed to apply their NSIP funding allocation to this objective for several years, but the overwhelming percentage of WSC funding allocations are used to fund the operation and maintenance of NSIP Federal-goal streamgages. It is estimated that less than 10 percent of the allocated NSIP funds are used to help meet this objective.

Recreating on a river.

Recreating on a river. Streamflow information is used by many recreationists to help ensure a safe and enjoyable experience.

Goal 2: Improved Delivery of Streamflow Data to Users

Developing new, state-of-the-art methods to transmit, store, and distribute streamflow information is an essential component of the NSIP. Improving the delivery of streamflow data includes a wide spectrum of activities, such as the automatic transmission of data from the streamgage on the river bank into the database, analysis of the rating curve, and reporting of and access to the data on the World Wide Web. Also included is ensuring the information is available when needed by establishing backup data-delivery systems and providing enhanced data-storage, -retrieval, and -analysis capabilities.