Data Library

This page serves as a collection of known data resources and tools to aid in planning and developing numeric nutrient criteria. Data resources are split into four sections:

  • Data repositories include lists of data already compiled by other agencies or organizations and often contain large quantities of available information.
  • Data sources are data from individual datasets that contain information related to water quality and criteria development.
  • Tools may provide platforms or materials to help organize and process data before beginning analyses.
  • Regional data include region-specific information that could be useful in gathering information at a regional scale.

This page provides links to non-EPA websites that provide additional information about this topic. You will leave the domain, and EPA cannot attest to the accuracy of information on that non-EPA page. Providing links to a non-EPA Web site is not an endorsement of the other site or the information it contains by EPA or any of its employees. Also, be aware that the privacy protection provided on the domain (Refer to Privacy and Security Notice) may not be available at the external link. The following links exit the site Exit

Data Repositories

One-stop shop locations for data access. Often a repository is a good place to start a search for data if you aren’t sure what data sources are available. is a clearinghouse for U.S. government data that allows users to search for a dataset by keyword or filter all datasets by topic, category, location, tag, format, and agency who collected the data. Types of data within include environmental, water quality, land cover, and other.

The National Map

The National Map is a web-based geospatial data viewing and access platform developed as a collaborative effort between USGS and other Federal, State, and local partners. Geospatial data available from the National Map include orthoimagery (aerial photographs), elevation (digital elevation models [DEMs]), geographic names and features, hydrography, boundaries, transportation, structures, and land cover.

NOAA National Center for Environmental Information (NCEI)

NOAA’s National Centers for Environmental Information (NCEI) are responsible for hosting and providing public access to one of the most significant archives for environmental data on Earth with over 20 petabytes of comprehensive atmospheric, coastal, oceanic, and geophysical data. NCEI is the ongoing consolidation of NOAA’s three existing National Data Centers: the National Climatic Data Center, the National Geophysical Data Center, and the National Oceanographic Data Center. As such, there is a variety of information stewarded by the NCEI and all data meet NOAA standards.

USDA Geospatial Data Gateway (GDG)

USDA’s Geospatial Data Gateway (GDG) provides access to a map library of over 100 high resolution vector and raster spatial data layers containing environmental and natural resources data. GDG allows users to choose an area of interest, browse and select data, customize the format, and download. Data can be sorted and by location and dataset type.

USGS Maps and GIS Data Links

USGS Maps and GIS Data Links provide access to USGS downloadable spatial data files.

NASA’s EarthData

NASA’s compiled list of remotely sensed data (including Landsat and MODIS) can be searched using EarthData Search, that allows for a temporal and spatial search of remotely sensed imagery. Thousands of layers and datasets are available to download, including land classification, soil profiles, and weather information. Links to non-NASA missions are also available.

Data Basin

Data Basin is a science-based mapping and analysis platform that provides open access to a massive and growing number of independent geospatial datasets (>10,000) from different parts of the world. Datasets are member-uploaded spatial information, typically created using a Geographic Information System (GIS). They can be visualized and analyzed using mapping tools in Data Basin, and downloaded for use in desktop GIS software. Datasets include shapefiles, ArcGRID files, ESRI File Geodatabases, and NetCDF files. Most datasets can be overlayed, styled, analyzed, and downloaded. The user-friendly web-interface makes it easy to search through datasets and download those that may be useful for stream analyses.


Data Sources

Water Quality (Water Chemistry and Biology) Data Sources

Water Quality Portal (WQP)

The Water Quality Portal is a partnership between the USGS, EPA, and the National Water Quality Monitoring Council (NWQMC). It provides data collected by over 400 state, federal, tribal, and local agencies. Refer to the Tools section for information on the WQP Data Discovery R Tool. The WQP provides an easy way to access data stored in various large water quality databases and includes discrete water quality and biological data compiled from the following growing list of databases in one location:

STORET (STOrage and RETrieval)

EPA’s STORET is a national database of water quality data including biological, physical, chemicals, and habitat data. STORET provides a platform for users (state and federal agencies, EPA, universities, private citizen, etc.) to manage data locally and share data nationally, allowing widespread access to local data. STORET is updated weekly on Thursday evening. Data recently added to STORET might not be immediately accessible through the WQP.

National Water Information System (NWIS)

USGS’s NWIS is a comprehensive and distributed application that supports the acquisition, processing, and long-term storage of water data. NWIS provides access to water-resources data collected at around 1.5 million sites across the U.S. and territories. Users can access real-time or historical data on water quality, surface water, groundwater, and water use through NWIS. NWIS is updated every 24 hours. Data recently added to NWIS might not be immediately accessible through WQP.

BioData Retrieval System

The USGS BioData Retrieval System provides access to aquatic bioassessment data (biological community [fish, macroinvertebrate, algae] and physical habitat data) collected by USGS scientists from stream ecosystems across the nation. Users can search and select data based on sample type, geography, site characteristics, sampling dates, and projects. The system contains sample data that were collected and processed using the National Water Quality Assessment (NAWQA) or EPA’s National Rivers and Streams Assessment Program’s protocols.

National Aquatic Resource Survey (NARS)

The National Aquatic Resource Surveys (NARS) are collaborative programs between EPA, states, and tribes to assess the quality of the nation’s waters. NARS provide nationally-consistent data on the condition of the nation’s coastal waters, lakes and reservoirs, rivers and streams, and wetlands based on a rotating basis. NARS data have been uploaded to STORET which is available through the WQP. Data can also be obtained directly from NARS. This database can be filtered by survey and by indicator.

EPA Environmental Monitoring and Assessment Program (EMAP) includes nutrient and biological response data collected from 1990 through 2006. This program was replaced by the NARS.

Sustaining The Earth’s Watersheds—Agricultural Research Database System (STEWARDS)

Sustaining The Earth’s Watersheds—Agricultural Research Database System (STEWARDS) is a web-based data delivery system to provide access to hydrologic, soil, water quality, climate, land-management, and socio-economic data from 17 watersheds through the USDA Agricultural Research Service (ARS).

National Water-Quality Assessment (NAWQA) Program

The USGS National Water-Quality Assessment Program (NAWQA) provides an understanding of water-quality conditions, whether conditions are getting better or worse over time, and how natural features and human activities affect those conditions. Monitoring data are integrated with geographic information on hydrological characteristics, land use, and other landscape features. Regional and national assessments are possible because of a consistent study design and uniform methods of data collection and analysis. Input data is available via the WQP.

USGS Water Quality Information

The USGS summary page of water quality data resources contains links to other USGS data resources, such as the Water Quality Portal, NWIS, BioData: Aquatic Bioassessment Data, and NAWQA. Many sources of freshwater monitoring data can be accessed here.

Assessment and Total Maximum Daily Load Tracking and Implementation System (ATTAINS)

EPA’s Assessment and Total Maximum Daily Load Tracking and Implementation System (ATTAINS) includes section 303(d) impaired waters, section 305(b) assessment information, and TMDL information presented nationally and by state reported to EPA by states.

Beach Advisory and Closing Online Notification (BEACON 2.0)

EPA’s Beach Advisory and Closing Online Notification (BEACON) system provides a database of pollution occurrences for coastal recreational waters. Data included in BEACON has been provided by coastal and Great Lakes states, and by tribes and territories that received grants under the BEACH Act. Users can select reports by location.

NOAA’s National Estuarine Research Reserve System (NERRS) Centralized Data Management Office (CDMO)

NOAA’s National Estuarine Research Reserve System (NERRS) data management system is used for water quality data from U.S. estuaries including over 14 million weather records, 50 million water quality records, and 100,000 nutrient records. NERRS is a network of 28 protected estuarine areas established by partnerships between NOAA and the coastal states. Data options include general data export, real-time viewing, GIS application, and vegetation monitoring.

NOAA’s Integrated Ocean Observing System (IOOS)

NOAA’s Integrated Ocean Observing System (IOOS) data access platform allows access to a variety of oceanographic and meteorological data including over 31,000 real-time environmental sensors through the environmental sensor map, which includes links to regional data portals.

USFS Water Quality Data

The U.S. Forest Service manages a large collection of air-quality-related water chemistry data. The datasets vary in spatial and temporal extent ranging in geographic size from a single lake to large regions. The data provided by USFS have been collected on Forest Service lands or by the Forest Service on adjacent lands. Users can search for monitoring locations by map or can query the database.

USGS National Water Census Data Portal

The USGS National Water Census Data Portal contains national estimates of water budget components (precipitation, evapotranspiration) for local watersheds, water withdrawal data for counties, tools to calculate statistics of daily streamflow records, modeled daily streamflow at ungagged stations, and access to records of aquatic biology observations.

Secchi Dip-In

The Secchi Dip-In is a volunteer-run program supported by the North American Lake Management Society and the EPA that has collected more than 41,000 records on more than 7,000 waterbodies across the United States since its inception 1994. Users can search for transparency data by location and water body.


Climate Data Sources

PRISM Climate Data

The PRISM Climate Group gathers climate observations from a wide range of monitoring networks, applies sophisticated quality control measures, and develops spatial climate datasets to reveal short- and long-term climate patterns. The resulting datasets incorporate a variety of modeling techniques and are available at multiple spatial/temporal resolutions, covering the period from 1895 to the present.

NOAA’s Advanced Hydrologic Prediction Service (AHPS)

National weather service precipitation data are quality-controlled, multi-sensor (radar and rain gauge) precipitation estimates obtained from National Weather Service (NWS) River Forecast Centers (RFCs). Precipitation data may be used in conjunction with other water quality and land use data to evaluate the effects of runoff on nutrient concentrations in surface water.

NOAA’s Precipitation Frequency Data Server (PFDS)

NOAA’s Precipitation Frequency Data Server (PFDS) is a point-and-click interface developed to deliver NOAA Atlas 14 precipitation frequency estimates and associated information. Estimates and their confidence intervals can be displayed directly as tables or graphs via separate tabs. Links to supplementary information (such as ASCII grids of estimates, associated temporal distributions of heavy rainfall, time series data at observation sites, cartographic maps, etc.) can also be found.

National Atmospheric Deposition Program (NADP)

The National Atmospheric Deposition Program (NADP) monitors precipitation chemistry. Monitoring networks with available data include the National Trends Network (NTN), Atmospheric Integrated Research Monitoring Network (AIRMoN), Mercury Deposition Network), Atmospheric Mercury Network, and the Ammonia Monitoring Network (AMoN).

Geography Data Sources

EPA and USGS’s National Hydrography Dataset (NHD) and NHDPlusV2

The National Hydrography Dataset (NHD) contains national geospatial surface water mapping with linked data. National Hydrography Dataset Plus (NHDPlus) is a national geospatial surface water framework (geofabric). Geospatial analysts and modelers use this framework to support water resources applications. EPA developed and maintains NHDPlus in partnership with USGS. The NHD and NHDPlus are used to portray surface water. These data represent the drainage network with features such as rivers, streams, canals, lakes, ponds, coastline, dams, and stream gages. The NHD uses a nominal scale of 1:24,000-scale. The NHDPlusV2 uses a courser nominal scale of 1:100,000 but builds upon the capabilities of NHD in integrating with other datasets with data such as StreamCat. The data in NHD are designed to be used in general mapping and in the analysis of surface water systems.

EPA’s StreamCat

The StreamCat Dataset provides summaries of natural and anthropogenic landscape features for ~2.65 million streams, and their associated catchments, within the conterminous USA. StreamCat data can be used to characterize both local and upstream features which are critical for effectively understanding, managing, and conserving riverine ecosystems. Similar data (LakeCat) on more than 356,000 USA lakes will be available within the next year (2017).

USGS’s Watershed Boundary Dataset (WBD) and Hydrological Unit Codes (HUCs)

The Watershed Boundary Dataset (WBD) is the latest classification system that is a nationally consistent watershed dataset subdivided into 6 levels (12 digit HUCs). The WBD contains the most current, the highest resolution and the most detailed delineation of the watershed boundaries, replacing the previous HUC coverages.

EPA’s Level III and IV Ecoregions

EPA’s Level III and IV Ecoregions are available as downloadable maps and GIS data files by state, EPA Region, and for the Continental U.S.. EPA has also aggregated Level III Ecoregions compiled to 14 regions using landscape characteristics related to nutrient concentrations in streams to help managers and researchers develop appropriate nutrient criteria.

USACE National Inventory of Dams (NID)

The USACE National Inventory of Dams (NID) is a congressionally authorized database documenting dams in the United States and its territories. It is maintained and published by the US Army Corps of Engineers (USACE). It contains information about a dam’s location, size, purpose, type, last inspection and regulatory facts as a spatial point dataset.

Multi-Resolution Land Characteristics Consortium National Land Cover Database (MRLC’s NLCD)

The Multi-Resolution Land Characteristics Consortium (MRLC) is a group of federal agencies that produce the National Land Cover Database (NLCD) with consistent land cover information at the national scale. The 2011 iteration is now available by NHDPlus drainage area.

NOAA’s Estuarine Bathymetry

NOAA’s Estuarine Bathymetry is a digital raster compilation of hydrographic survey data for selected U.S. estuaries.

NOAA’s Shoreline Data

NOAA’s Shoreline Data is a compilation of NOAA and other federal shoreline spatial data sets with descriptions of data attributes.

USDA-NRCS Soils: Web Soil Survey (WSS)

Web Soil Survey (WSS) provides soil data and information produced by the National Cooperative Soil Survey. These data include both SSURGO, detailed county-level data, and STATSGO2, less detailed state- or national-level data survey data. For more information refer to SSURGO and STATSGO2.

USGS’s Elevation data: 3DEP and the National Elevation Dataset (NED)

Data on America’s elevation have typically been represented as contour lines and bare earth digital elevation models (DEMs) in The National Map that was called the National Elevation Dataset (NED). With the 3D Elevation Program (3DEP) operational, light detection and ranging (lidar) and interferometric synthetic aperture radar (ifsar) data (in Alaska) are now the primary sources of elevation data for 3DEP, and provide opportunities for measuring, mapping and monitoring not only the bare earth surface, but above ground features as well. As a result, in addition to the traditional bare earth DEMs, USGS now provides the source lidar point clouds, ifsar digital surface models (DSMs) and orthorectified radar intensity images (ORIs) over every area where data have been acquired for 3DEP and The National Map. With 3DEP operational, the seamless bare earth DEMs that were called “NED” have been renamed and are considered just one component of elevation in The National Map.

USDA’s National Agricultural Statistics Service (NASS) Data and Statistics Page

USDA’s National Agricultural Statistics Service (NASS) data and statistics page includes quick agricultural statistics as well as spatial data hosted through CropScape and VegScape and the Census of Agriculture.  More information:


CropScape is a geospatial data service which offers access to the Cropland Data Layer (CDL). The purpose of the Cropland Data Layer Program is to use satellite imagery to provide acreage estimates to the Agricultural Statistics Board for the state’s major commodities and to produce digital, crop-specific, categorized geo-referenced output products.


VegScape is a geospatial data service which offers automated updates of vegetative condition at daily, weekly, and biweekly intervals. VegScape delivers interactive vegetation indices that enable quantification of U.S. crop conditions for exploring, visualizing, querying, and disseminating via interactive maps.

Agricultural Census

Published Agricultural Census material are comprehensive summaries of agricultural activity for the United States and for each state. Includes number of farms by size and type, inventory and values for crops and livestock, operator characteristics, and much more.

U.S. Census Bureau Topologically Integrated Geographic Encoding and Referencing (TIGER)

U.S. Census Bureau Topologically Integrated Geographic Encoding and Referencing (TIGER) products are spatial extracts from the Census Bureau’s MAF/TIGER database, containing features such as roads, railroads, rivers, as well as legal and statistical geographic areas. The Census Bureau offers several file types and an online mapping application, the Census Data Mapper.

U.S. Fish & Wildlife’s National Wetlands Inventory (NWI)

The National Wetlands Inventory (NWI) includes information about wetlands within the 48 states and American Samoa. The Wetlands Mapper is designed to deliver easy-to-use, map like views of America’s Wetland resources. It integrates digital map data along with other resource information to produce current information on the status, extent, characteristics and functions of wetlands, riparian, and deepwater habitats. Data can also be downloaded by HUC 8 watershed boundary or by state.

Facility Data Sources

EPA’s Envirofacts

Envirofacts is EPA’s one-stop source for facility-related environmental information. Users can search by topic, which include water, waste, and toxics, or by location. Specific programs or projects can also be searched individually.

EPA’s NPDES Dischargers Search—Permit Compliance System (PCS) and Integrated Compliance Information System (ICIS)

Permit Compliance System (PCS) and Integrated Compliance Information System (ICIS) Search is a platform that allows a search of the PCS and ICIS databases in Envirofacts regarding facilities registered with the federal enforcement and compliance (FE&C) and holding National Pollutant Discharge Elimination System (NPDES) permits. Users can search by location, facility, and parameter to determine discharges potentially affecting their water bodies of interest.


Data processing tools and resources.

N-STEPS Statistical Tools Fact Sheets

N-STEPS Online has compiled fact sheets on available statistical tools associated with numeric nutrient criteria derivation. These factsheets include a description of each of the statistical tools, their data requirements, how they work, statistics to look for and report, and an explanation on their relevance to numeric nutrient criteria development.

Statistical Packages

Modern computers and software packages make it simple to perform statistical analyses. Most standard spreadsheet programs include basic statistical functions and graphing capabilities, but more sophisticated and powerful statistical software packages might be needed for advanced analyses such as ANCOVA or cluster analysis. An extensive list and comparison of statistical software packages is available at Wikipedia. Practical Statistics, a web site maintained by Dennis Helsel, provides a more environmental-centric review of low-cost software tools (USEPA 2016, 7-108).


Several useful packages have been developed for the open source statistical software package R that are described. Analysts can turn to R (R Core Team 2013), a freely available software environment for statistical computing and graphics from the Comprehensive R Archive Network (CRAN). R provides a wide array of open source statistical and graphical tools that are collaboratively developed through an international community. Universities are quickly adopting R as an integral coursework component across many areas of study.

Downloading R

R can be downloaded here. Additional information is available in a short (four-page) reference card, a (76-page) beginner’s guide, and a comprehensive manual. Users might also find it helpful to use R from an integrated development environment such RStudio.

Installing R

Installing R includes installing a standard set of R packages including base, stats, methods, and graphics. Packages are a collection of R functions, data, and code. It is common among most analysts to install additional packages that broaden R’s functionality. Thousands of packages are available from the CRAN, Bioconductor , and GitHub . Some additional packages that might be helpful include some of the following:

dplyr  – Functions for subsetting, summarizing, rearranging, and joining together data sets.

tidyr – Functions to change the layout of data between long and wide formats.

lubridate  – Functions to improve ease of working with dates and time.

ggplot2  – Functions that provide additional functionality for graphics relative to standard functionality.

ggmap  – Functions to download street maps directly from Google maps and use them as a background in ggplots.

NADA  – Functions for computing summary statistics and hypothesis testing with censored data.

car  – Functions to compute type II and type III ANOVA tables.

mgcv  – Functions to develop mixed generalized additive models (GAMs).

randomForest  – Functions that perform classification and regression based on a forest of trees using random inputs.

dataRetrieval  – This R package is designed to obtain its water quality sample data, streamflow data, and metadata directly from either the USGS or EPA.

USGS packages  – Repository of several R packages (e.g., smwrQW, smwrStats, etc.) useful for applying statistical methods for water resources.

EPA’s Water Quality Portal (WQP) Data Discovery Tool

The Water Quality Portal (WQP) Data Discovery tool is a desktop application that provides an easy to use interface allowing users to search, summarize, QC, and display data from the WQP. The tool uses R and several add-on packages, to visualize the data selected from the portal and to assist users in data analysis.

EPA’s Nitrogen and Phosphorus Pollution Data Access Tool (NPDAT)

EPA’s Nitrogen and Phosphorus Pollution Data Access Tool (NPDAT) is a web-based mapper tool that is used to select nitrogen and phosphorus related data. Data include: 1. SPARROW model total nitrogen and phosphorus yields 2. nitrogen and phosphorus water quality data from STORET/NWIS/NARS; 3. Nitrogen and phosphorus impairments, TMDLs, and discharger facilities.

EPA’s Discharge Monitoring Report (DMR) Pollutant Loading Tool

The Discharge Monitoring Report (DMR) Pollutant Loading Tool is designed to help users determine who is discharging, what pollutants they are discharging and how much, and where they are discharging. The tool calculates pollutant loadings from permit and DMR data from EPA’s Integrated Compliance Information System for the National Pollutant Discharge Elimination System (ICIS-NPDES). Data are available from the year 2007 to the present. Pollutant loadings can provide information on nutrients in waterways which may help inform nutrient criteria development.

EPA’s Open Waters: Water Quality Data Management System

Open Waters is a free and open-source web-based water quality data management software for submitting water quality data to EPA using Exchange Network technologies. Open Waters helps state and tribal water quality managers track monitoring locations, projects, samples, and results. Users can manage their data locally and submission to EPA is automated.

EPA’s National Stormwater Calculator

EPA’s National Stormwater Calculator desktop application that estimates the annual amount of rainwater and frequency of runoff from a specific site anywhere in the United States (including Puerto Rico), based on available information. Estimates are based on local soil conditions, land cover, and historic rainfall records. The calculator is designed to be used by anyone interested in reducing runoff. It accesses several national databases that provide soil, topography, rainfall, and evaporation information.


EPA’s MyWATERS Mapper dynamically displays snapshots of EPA Office of Water program data. This version of MyWATERS Mapper depicts the status of NPDES permits for each State, summary information from the Clean Watershed Needs Survey, and water quality assessments. Data can be downloaded based on geographic area. Specific water quality impairment data (nutrients, sediments, and pathogens) and other water information can be visualized in the Mapper and downloaded.

EPA’s How’s My Waterway? Tool

The How’s My Waterway? interface is a user-friendly tool for searching water quality information by zip code or by current location. The tool reports water quality status, and provides links to technical documents. The information provided by the interface may be useful in initial evaluation of a water body to examine past conditions and what steps have already been taken for remediation.

EPA’s Clip N Ship Dischargers Application

The Clip N Ship application allows users to download files of the locations of State Pollution Discharge Elimination System (SPDES) permit holders, federal and state water quality sampling sites, and other base information about watersheds and waterways. Users can choose from a variety of file formats, including those compatible with Google Earth and ArcGIS. Information on discharging permits may provide insight into potential pollutant loadings in a given watershed.

USGS Water Resources Surface Water Software

The USGS Water Resources Surface Water Software provides a list of publicly available USGS water resources software and statistics packages.

USGS StreamStats

StreamStats is a Web application that incorporates a Geographic Information System (GIS) to provide users with access to an assortment of analytical tools that are useful for a variety of water-resources planning and management purposes, and for engineering and design purposes. Users can select data-collection stations from a map and obtain information about the locations as well as interact with the map to perform various analytical techniques involving the available data.

EPA’s Hydrologic and Water Quality System (HAWQS)

The Hydrologic and Water Quality System (HAWQS) is a web-based interactive water quantity and quality modeling system that employs as its core modeling engine the Soil and Water Assessment Tool (SWAT) model. HAWQS provides users with interactive web interfaces and maps, pre-loaded input data, outputs that include tables, charts, and raw output data, a user guide, and online development, execution, and storage of a user’s modeling projects. HAWQS includes a modeling system that can simulate water quality impacts across a very large geographic area and can support decision-making systems for watershed management.

EPA’s Causal Analysis/Diagnosis Decision Information System (CADDIS) Interactive Conceptual Diagram (ICD) Application

In Causal Analysis/Diagnosis Decision Information System (CADDIS), conceptual diagrams illustrate hypothesized pathways by which human activities and associated sources and stressors may lead to biotic responses in aquatic systems. The interactive conceptual diagram application builds upon this role for these diagrams, linking supporting literature to hypothesized causal pathways and using conceptual diagrams as the front-end for searching an online citation database of this literature-based information. The application includes a set of EPA-constructed conceptual diagrams, an online graphical editor, and a collaborative workspace.

Nutrient Toolkit

The Nutrient Toolkit is an organization of links to State and NGO resources intended to help State Water Quality Regulators assess their ability to adopt and, where applicable, implement numeric nutrient criteria. The Toolkit was prepared by The Association of Clean Water Administrators (ACWA).

EPA’s Estuary Data Mapper (EDM)

The Estuary Data Mapper (EDM) pulls together data collected from estuaries along the five U.S. coastal regions and provides a fast, easy way for researchers to examine a specific estuary of interest and find current, available data from many sources. EDM allows input to a GIS-based data model and contains several data types, including tidal, hydrologic, weather, water quality, sediment quality, and ground water. EDM also includes information about coastal rivers, tributaries, and watersheds and allows users to display background information to explore areas of interest, such as potential nutrient loading sources.

Automated Geospatial Watershed Assessment (AGWA) Tool

The Automated Geospatial Watershed Assessment (AGWA) tool is a GIS-based hydrologic modeling tool that uses commonly available GIS data layers to fully parameterize, execute, and spatially visualize results for the RHEM, KINEROS2, KINEROS-OPUS, SWAT2000, and SWAT2005 watershed runoff and erosion models. Accommodating novice to expert GIS users, it is designed to be used by watershed, water resource, land use, and resource managers and scientists investigating the hydrologic impacts of land-cover/land-use change in small watershed to basin-scale studies.

Regional Data

Data sources applicable to a particular region.

Chesapeake Bay Program (CBP) Data Hub

The Chesapeake Bay Program (CBP) Data Hub is interface provides access to several types of data related to the Chesapeake Bay. Chesapeake Bay Program databases can be queried based upon user-defined inputs such as geographic region and date range. Each query results in a downloadable, tab- or comma-delimited text file that can be imported to any program (e.g., SAS, Excel, Access) for further analysis.

U.S. Bureau of Reclamation Water Operations

The Bureau of Reclamation Water Operations manages many irrigation and water supply reservoirs in the West, some of which may have operational data available. These data focus on water supply information and limited water quality data. However, real time flow data are collected for rivers supplying water to BuRec, which may be useful for the flow component of criteria development.

NOAA’s Gulf of Mexico Data Atlas

Based on the idea of a traditional atlas but offered via the Internet by NOAA, the Gulf of Mexico Data Atlas provides answers to questions related to the physical environment, marine resources, and economic activity in the Gulf of Mexico. The Gulf of Mexico Atlas has data from all five Gulf States (Alabama, Florida, Louisiana, Mississippi, and Texas). Maps are available in six topic areas:

  1. Physical (e.g., bathymetry, climatology)
  2. Biotic (chemosynthetic communities, aquatic vegetation)
  3. Living Marine Resources (oysters, shrimp, grouper)
  4. Economic Activity (shipping & navigation, oil & gas)
  5. Environmental Quality (water quality, discharges)
  6. Jurisdictions (marine, fishery closures)

Regional Harmful Algal Blooms Resources

NOAA Harmful Algal Bloom Operational Forecast System (HAB-OFS) – Resources by Region

NOAA’s HAB-OFS website provides a list of other HAB resources, organized by region.

NOAA’s Gulf of Mexico Data Harmful Algal BloomS Observing System (HABSOS)

NOAA’s Gulf of Mexico Data Harmful Algal BloomS Observing System (HABSOS) is a data collection and distribution system for harmful algal bloom (HAB) information in the Gulf of Mexico. Cell counts and environmental information are combined into a single product and distributed on a map powered by ArcGIS. HABSOS strives to provide an accurate picture of HAB location and quantity.

Northwest Association of Networked Ocean Observing systems (NANOOS) Algal Bloom Data

Northwest Association of Networked Ocean Observing systems (NANOOS) provides data analysis products such as modeled current and temperature forecasts and real time data critical to resource managers, shellfish growers and researchers’ decision making in terms of managing for HABS.

Central and Northern California Ocean Observing System (CeNCOOS) Algal Bloom Data

Central and Northern California Ocean Observing System (CeNCOOS) algal bloom data includes HAB forecasts and observations in northern and central California.

Southern California Coastal Ocean Observing System (SCCOOS) Algal Bloom Data

Southern California Coastal Ocean Observing System (SCCOOS) is a data collection and distribution system for harmful algal bloom (HAB) information off the coast of southern California. Users can navigate a regional map and examine data on potentially harmful algal species and water conditions at regional stations.

Great Lakes Observing System (GLOS) HABS Data Portal

The Great Lakes Observing System (GLOS) HABS Data Portal provides convenient access to data used to monitor conditions in Lake Erie and to alert those making decisions regarding harmful algal blooms and water treatment.

Great Lakes Observing System (GLOS)

Great Lakes Observing System (GLOS) works to make real-time and historical data publicly available to the larger Great Lakes community, benefiting data users and decision makers. Tools through the GLOS interface allow users to access, browse, and download data or datasets. Data available through GLOS includes near-real time data for point observations, satellite observations, and model forecasts of water quality and weather conditions. Access the GLOS data portal for spatial web access.

Gulf of Mexico Alliance GOMAportal

The Gulf of Mexico Alliance GOMAportal is a metadata catalog and data repository for Gulf of Mexico related geospatial datasets. Funded by the Gulf of Mexico Alliance (GOMA), GOMAportal houses the results of a multi-year project by the GOMA Ecosystems Integration and Assessment (EIA) Priority Issue Team (PIT) to improve the state metadata for geospatial datasets for the Gulf of Mexico.

Ohio River Valley Water Sanitation Commission (ORSANCO)

Ohio River Valley Water Sanitation Commission (ORSANCO) is an interstate commission representing eight states and the federal government. Member states include: Illinois, Indiana, Kentucky, New York, Ohio, Pennsylvania, Virginia, and West Virginia. ORSANCO performs biological assessments and monitors the chemical and physical properties of waterways along the Ohio River. Available data includes measures of various nutrients, physical and physical water properties, and toxicity measurements.

U.S. Forest Service’s NorWeST Stream Temperature Project

The NorWeST webpage hosts stream temperature data and climate scenarios in a variety of user-friendly digital formats for streams and rivers across the western U.S. The temperature database was compiled from hundreds of biologists and hydrologists working for >100 resource agencies and contains >150,000,000 hourly temperature recordings at >20,000 unique stream sites.

USGS SPARROW Model Assessments of Streams and Rivers

USGS SPARROW models have been developed for seven large regions of the coterminous United States. Results from the models can be used to compare nutrient sources and watersheds that contribute elevated nutrient loads to downstream receiving waters. The models have been incorporated into an interactive, online decision support system so that water managers, researchers, and the general public can access SPARROW models and map predictions of long-term average water quality conditions.

Case Studies

Minnesota Lakes

  • MPCA based NNC by ecoregion on data from independent studies and STORET, and new data
  • Percentiles of reference lake characteristics helped establish criteria recommendations

Wisconsin Streams

  • USGS and WDNR sampled 280 streams for discharge and water quality in support of nutrient criteria
  • Geospatial data was used from USGS, STATSGO, and NCDC
  • A multiple linear regression model related water quality to anthropogenic characteristics

Maine Fresh Surface Water

  • Based TP and chlorophyll a criteria on conditional probability analyses and reference conditions
  • Data used in the analysis were collected over several years
  • Paired samples of TP and Secchi depth were analyzed
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