The Pennsylvania Department of Environmental Protection relies upon a number of parameters to monitor water-supply-drought conditions, including precipitation, streamflow, groundwater levels, and Palmer Drought Index, an indicator of soil dryness.
Pennsylvania Department of Environmental Protection Drought Information
Streamflow and groundwater levels are provided by USGS. Other data sources are PRISM Climate Group for precipitation, and the National Centers for Environmental Information's North American Drought Monitor (NADM) for Palmer Drought Index (soil moisture dryness), Percent Precipitation, and Standardized Precipitation Index. Patterns in the USGS-provided data can be explored using the Web Tool.
These parameters are used only as indicators of the four stages of drought that the Pennsylvania Department of Environmental Protection uses for drought management—normal, watch, warning, and emergency. Actual declarations of any particular drought stage in a given county are based upon a review of these parameters in combination with other considerations. No one parameter or combination of particular parameters automatically establishes a stage of drought. The background colors of the counties in the maps presented herein represent Pennsylvania's current officially-declared status of the counties.
Drought Watch
A drought watch is intended to alert government agencies, public water suppliers, water users and the public regarding the onset of conditions indicating the potential for future drought-related problems. The focus during this stage is on increased monitoring, awareness and preparation for response if conditions become worse. A request for voluntary water conservation is made. The objective of voluntary water conservation measures during a drought watch is to reduce water uses by 5% in the affected areas. Because of varying conditions, individual water suppliers or municipalities may be asking for more stringent conservation actions.
Drought Warning
A drought warning implements coordinated response to imminent drought conditions and potential water supply shortages and initiates concerted voluntary conservation measures to avoid or reduce shortages, relieve stressed sources and forestall the need to impose mandatory water use restrictions. Development of alternate sources is initiated where and as appropriate. The objective of voluntary water conservation measures during a drought warning is to reduce overall water uses by 10-15% in the affected areas. Because of varying conditions, individual water suppliers or municipalities may be asking for more stringent conservation actions.
Drought Emergency
A drought emergency is a concentrated management phase designed to marshal all available resources to respond to actual emergency conditions, to avoid depletion of water sources, to assure at least minimum water supplies to protect public health and safety, to support essential and high priority water uses and to avoid unnecessary economic dislocations. During this phase, mandatory restrictions are imposed on nonessential water uses as provided for in 4 PA Code Chapter 119. The objective of water use restrictions and other conservation measures during this phase is to reduce consumptive water use in the affected area by at least 15 percent, and to reduce total use to the extent necessary to preserve public water system supplies, to avoid or mitigate local or area shortages, and to assure equitable sharing of limited supplies. During a drought emergency, public water suppliers are authorized to institute water rationing, if mandatory restrictions prove insufficient to protect supplies and if approved by the Commonwealth Drought Coordinator.
USGS Waterwatch Low-Flow Conditions
Average streamflow maps:
- Area map: Below normal 7-day
- Site map: Below normal 7-day
- Site map: Below normal 14-day
- Site map: Below normal 28-day
Drought Analyses and Management
- Drought FAQs (USGS Open-File Report): Drought
- Drought and climate | evapotranspiration
- Pennsylvania DEP: Drought Management in Pennsylvania
Drought Links
- NOAA's climate outlook maps
- U.S. Drought Monitor map and summary
- NOAA's Drought Information Center
- NRCS weekly drought reports, SNOTEL data, water-equivalent, and precipitation graphs by basin
- National Weather Service
Science
Droughts: Things to Know
Forecasting drought probabilities for streams in the northeastern United States
Evaluating low flow patterns, drivers and trends in the Delaware River Basin
Spatial and temporal patterns of low streamflow and precipitation changes in the Chesapeake Bay Watershed
Hydro-climatic drought in the Delaware River Basin
Drought forecasting for streams and groundwaters in northeastern United States
Drought-sensitive aquifer settings in southeastern Pennsylvania
Water loss in the Potomac River basin during droughts
Palmer Drought Severity Index as a Measure of Hydrologic Drought
Water quality in the Delaware estuary for two years of drought: 1965 and 1966, from Trenton, New Jersey to Reedy Island, Delaware
Pennsylvania Drought Condition Monitoring
The Pennsylvania Drought Condition Monitoring Application shows the current drought status for each county and hydrologic conditions for precipitation, streamflow, groundwater levels, and Palmer Drought-Severity Index used by PaDEP for drought monitoring.
- Overview
The Pennsylvania Department of Environmental Protection relies upon a number of parameters to monitor water-supply-drought conditions, including precipitation, streamflow, groundwater levels, and Palmer Drought Index, an indicator of soil dryness.
Pennsylvania Department of Environmental Protection Drought InformationStreamflow and groundwater levels are provided by USGS. Other data sources are PRISM Climate Group for precipitation, and the National Centers for Environmental Information's North American Drought Monitor (NADM) for Palmer Drought Index (soil moisture dryness), Percent Precipitation, and Standardized Precipitation Index. Patterns in the USGS-provided data can be explored using the Web Tool.
These parameters are used only as indicators of the four stages of drought that the Pennsylvania Department of Environmental Protection uses for drought management—normal, watch, warning, and emergency. Actual declarations of any particular drought stage in a given county are based upon a review of these parameters in combination with other considerations. No one parameter or combination of particular parameters automatically establishes a stage of drought. The background colors of the counties in the maps presented herein represent Pennsylvania's current officially-declared status of the counties.
Drought Watch
A drought watch is intended to alert government agencies, public water suppliers, water users and the public regarding the onset of conditions indicating the potential for future drought-related problems. The focus during this stage is on increased monitoring, awareness and preparation for response if conditions become worse. A request for voluntary water conservation is made. The objective of voluntary water conservation measures during a drought watch is to reduce water uses by 5% in the affected areas. Because of varying conditions, individual water suppliers or municipalities may be asking for more stringent conservation actions.
Drought Warning
A drought warning implements coordinated response to imminent drought conditions and potential water supply shortages and initiates concerted voluntary conservation measures to avoid or reduce shortages, relieve stressed sources and forestall the need to impose mandatory water use restrictions. Development of alternate sources is initiated where and as appropriate. The objective of voluntary water conservation measures during a drought warning is to reduce overall water uses by 10-15% in the affected areas. Because of varying conditions, individual water suppliers or municipalities may be asking for more stringent conservation actions.
Drought Emergency
A drought emergency is a concentrated management phase designed to marshal all available resources to respond to actual emergency conditions, to avoid depletion of water sources, to assure at least minimum water supplies to protect public health and safety, to support essential and high priority water uses and to avoid unnecessary economic dislocations. During this phase, mandatory restrictions are imposed on nonessential water uses as provided for in 4 PA Code Chapter 119. The objective of water use restrictions and other conservation measures during this phase is to reduce consumptive water use in the affected area by at least 15 percent, and to reduce total use to the extent necessary to preserve public water system supplies, to avoid or mitigate local or area shortages, and to assure equitable sharing of limited supplies. During a drought emergency, public water suppliers are authorized to institute water rationing, if mandatory restrictions prove insufficient to protect supplies and if approved by the Commonwealth Drought Coordinator.
USGS Waterwatch Low-Flow Conditions
Average streamflow maps:
- Area map: Below normal 7-day
- Site map: Below normal 7-day
- Site map: Below normal 14-day
- Site map: Below normal 28-day
Drought Analyses and Management
- Drought FAQs (USGS Open-File Report): Drought
- Drought and climate | evapotranspiration
- Pennsylvania DEP: Drought Management in Pennsylvania
Drought Links
- NOAA's climate outlook maps
- U.S. Drought Monitor map and summary
- NOAA's Drought Information Center
- NRCS weekly drought reports, SNOTEL data, water-equivalent, and precipitation graphs by basin
- National Weather Service
- Science
Science
Droughts: Things to Know
The following topics provide background on some of the scientific issues regarding droughts. - Publications
Forecasting drought probabilities for streams in the northeastern United States
Maximum likelihood logistic regression (MLLR) models for the northeastern United States forecast drought probability estimates for water flowing in rivers and streams using methods previously identified and developed. Streamflow data from winter months are used to estimate chances of hydrological drought during summer months. Daily streamflow data collected from 1,143 streamgages from April 1, 187AuthorsSamuel H. AustinEvaluating low flow patterns, drivers and trends in the Delaware River Basin
In the humid, temperate Delaware River Basin (DRB) where water availability is generally reliable, summer low flows can cause competition between various human and ecological water uses. As temperatures continue to rise, population increases and development expands, it is critical to understand historical low flow variability to anticipate and plan for future flows. Using a sample of 325 U.S. GeolAuthorsJohn C. Hammond, Brandon J. FlemingSpatial and temporal patterns of low streamflow and precipitation changes in the Chesapeake Bay Watershed
Spatial and temporal patterns in low streamflows were investigated for 183 streamgages located in the Chesapeake Bay Watershed for the period 1939–2013. Metrics that represent different aspects of the frequency and magnitude of low streamflows were examined for trends: (1) the annual time series of seven‐day average minimum streamflow, (2) the scaled average deficit at or below the 2% mean daily sAuthorsBrandon J. Fleming, Stacey A. Archfield, Robert M. Hirsch, Julie E. Kiang, David M. WolockHydro-climatic drought in the Delaware River Basin
The Delaware River Basin (DRB) supplies water to approximately 15 million people and is essential to agriculture and industry. In this study, a monthly water balance model is used to compute monthly water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff [R]) for the DRB for the 1901 through 2015 period. Water‐year R is used to identify drought periods iAuthorsGregory J. McCabe, David M. WolockDrought forecasting for streams and groundwaters in northeastern United States
BackgroundWhen rainfall is lower than normal over an extended period, streamflows decline, groundwater levels fall, and hydrological drought can occur. Droughts can reduce the water available for societal needs, such as public and private drinking-water supplies, farming, and industry, and for ecological health, such as maintenance of water quality and natural ecosystems. Recent droughts in the noAuthorsSamuel H. Austin, Robert W. DudleyDrought-sensitive aquifer settings in southeastern Pennsylvania
This report describes the results of a study conducted by the U.S. Geological Survey, in cooperation with the Pennsylvania Department of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey, to determine drought-sensitive aquifer settings in southeastern Pennsylvania. Because all or parts of southeastern Pennsylvania have been in drought-warning or drought-emergency statusAuthorsTammy M. Zimmerman, Dennis W. RisserWater loss in the Potomac River basin during droughts
The water loss phenomena in the Washington DC metropoliton area's (WMA) Potomac River water supply basin during droughts was analyzed. Gage errors, permitted withdrawals, evaporation, and transpiration by trees along the river were investigated to account for loss. The Interstate Commission on the Potomac River Basin (ICPRB) calculated potential gage error and examined permits to determine permittAuthorsE.R. Hagen, J.E. Kiang, J.J.A. DillowPalmer Drought Severity Index as a Measure of Hydrologic Drought
The Palmer Drought Severity Index (PDSI) for climatic divisions in New Jersey is compared to the occurrence within each climatic division of streamflows in their lower quartile for the month (streamflow index) and ground-water levels in their lower quartile for the month (ground-water index). These indices are found to have distinct properties. The PDSI values and groundwater index indicate more pAuthorsWilliam M. AlleyWater quality in the Delaware estuary for two years of drought: 1965 and 1966, from Trenton, New Jersey to Reedy Island, Delaware
No abstract available.AuthorsWalter B. Keighton - Web Tools
Pennsylvania Drought Condition Monitoring
The Pennsylvania Drought Condition Monitoring Application shows the current drought status for each county and hydrologic conditions for precipitation, streamflow, groundwater levels, and Palmer Drought-Severity Index used by PaDEP for drought monitoring.
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