Approved by the Energy, Environment, and Water Policy Committee on February 17, 2022 
Approved by the Public Policy and Practice Committee on May 18, 2022
Adopted by the Board of Direction on July 22, 2022


The American Society of Civil Engineers (ASCE) supports federal, state, and local governments’ continuation of long-term hydrologic data collection and expansion of those efforts for major and minor watersheds. Funding should be provided on a continuing basis sufficient to allow prediction of changing storm patterns, major flood events, sediment transport and the interaction of water and soil through river systems.


Hydrologic data measurements of precipitation, streamflow, groundwater, and evapotranspiration are vitally important to water resource planning, regional sediment management for reservoirs and navigable waterways, and flood-risk management, as well as the design and operation of most infrastructure projects. Such data are critical for performing risk assessment and economic analysis properly, and for evaluating the impact of infrastructure projects on public health, welfare, safety, and the environment. Reliable historical data are essential for the modeling necessary to make accurate predictions. Most importantly, because these data must be collected on a regional basis, this is inherently a federal responsibility. Many United States (U.S.) agencies, in particular the National Weather Service, the U.S. Geological Survey, and the Department of Agriculture provide the foundation of the basic data collection program for water in the U.S. Federal agencies such as these have the most comprehensive and continuous historical hydrologic data collection in the United States. This has been supplemented by additional data provided by state and local agencies. Given the recent changes to storm events in intensity and duration it is imperative to maintain continuous data records in order to track the historic trends. Inadequate and uncoordinated hydrologic data collection, resulting from budget shortages or redirection of resources, has long term adverse effects on the efficiency and certainty of planning, design, construction, and operation of water and other projects and results in an unnecessary and significant risk to the public safety.

The lack of adequate data impacts the ability to model, predict and plan for catastrophic events. Events such as floods and droughts, have significant impacts on public health, safety, welfare, and our nation's economy.


Hydrological data are essential when combined with meteorological, and water quality data for integrated watershed management, floodplain management, and regional sediment management. This helps inform regulators at a federal, state, and local level for updating and maintaining guidance documents and regulations for planning, design. and construction. The data should be used for the design of the drainage component of infrastructure projects, in addition to water supply, flood control, navigation, and development projects. Collection, analysis, and dissemination of continuous hydrologic data are critical for effective modeling, forecasting, and all types of water resource management.

ASCE Policy Statement 447 
First Approved 1996