Tools for evaluating aquatic resource condition

Factor used in analysis

Data source(s)

Watershed-level disturbance

Watershed percent agriculture

NLCD 1992⁽⁴⁾; NLCD 2001⁽⁵⁾; NLCD 2006⁽⁶⁾; various state sources for land cover data; USGS cropland data by county⁽⁷⁾; NHDplus catchments⁽⁴⁾; USDA national GIS crop dataset⁽⁸⁾; BLM dataset on range allotments and pastures⁽⁹⁾

Watershed percent steep slope agriculture

NLCD 1992⁽³⁾; NLCD 2001⁽⁴⁾; NLCD 2006⁽⁵⁾; various state source for land cover data; USGS cropland data⁽⁷⁾; USGS NED⁽⁶⁾; USGS EDNA⁽⁷⁾; NHDplus flowline elevation data⁽⁴⁾

Watershed number of CAFOs

State records mapping CAFO locations and livestock species and numbers

Watershed number of septic systems (zones of potential septic usage and assumed partial failure rates)

Non-sewered area maps; municipality-level individual septic records; septic failure rate coefficient from watershed studies and TMDLs

Watershed percent impervious cover

NLCD 2001⁽⁴⁾; NLCD 2006⁽⁵⁾; NHDplus catchments⁽⁴⁾

Watershed percent tile-drained cropland

State-level digital soil survey data; NRCS Soil Data Mart⁽⁸⁾; NLCD 1992⁽³⁾; NLCD 2001⁽⁴⁾; NLCD 2006⁽⁵⁾; various state sources of land cover data; USGS cropland by county⁽⁶⁾; USDA national GIS crop dataset⁽⁷⁾

Watershed percent U index (percent anthropogenic cover types)

NLCD⁽²⁾; statewide land cover data from state-specific sources

Watershed percent urban

NLCD⁽²⁾; statewide land cover data from state-specific sources

Watershed road density (mean road length per watershed square mile)

Transportation GIS datasets; national road and stream data from the National Atlas⁽¹⁰⁾; ESRI roads dataset⁽¹¹⁾

Other percent watershed stressor (e.g., surface mining for some watersheds)

Dependent upon additional stressors identified

Corridor and shoreland disturbance

Corridor percent impervious cover

NLCD 2001⁽⁴⁾ and 2006⁽⁵⁾ data for impervious and urban land cover; NHDplus catchments⁽⁴⁾

Corridor percent tile-drained cropland

State-level digital soil survey data; NRCS Soil Data Mart⁽⁸⁾; NLCD 1992⁽³⁾; NLCD 2001⁽⁴⁾; NLCD 2006⁽⁵⁾; various state sources of land cover data; USGS cropland by county⁽⁶⁾; USDA national GIS crop dataset⁽⁷⁾

Corridor percent U-index (percent anthropogenic land cover types)

NLCD⁽²⁾; statewide land cover data from state-specific sources

Corridor percent urban

NLCD⁽²⁾; statewide land cover data from state-specific sources

Corridor percent agriculture

NLCD 1992, NLCD 2001; NLCD 2006; various state sources for land cover data; USGS cropland by county⁽⁶⁾; USDA national GIS crop dataset⁷; BLM data on range allotments and pastures⁽⁸⁾

Linear percent of channel through agriculture (percent total stream length through agricultural land use or percent agricultural area adjacent to stream)

Stream hydrography data; land cover data

Corridor road crossings

National road and stream data from the National Atlas⁽⁹⁾; Landsat data for roads and stream from USGS Earth Explorer⁽¹²⁾; ESRI roads dataset⁽¹⁰⁾; data for unimproved road crossings in remote parts of federal lands from land management agency

Corridor road density

National road and stream data from the National Atlas⁽⁹⁾; ESRI roads dataset⁽¹⁰⁾

Hydrologic alteration

Aquatic barriers (count per watershed or relative isolation of specific stream segment of similar Strahler order)

Aquatic barriers to fish passage from the USFWS Decision Support System⁽¹³⁾; major dams mapping by the USACE National Inventory of Dams⁽¹⁴⁾; NHD data on dams and divergence structures⁽⁶⁾

Channelization (percent of total impaired stream length artificially straightened)

USGS NHD⁽⁶⁾; local resources; channelization attribute data for 303(d) listed streams included in EPA ATTAINS data system⁽²⁰⁾

Hydrologic alteration (scores waterbody segments downstream of dams or withdrawals based on dam size, active status, role on flow alteration and feasibility of flow management)

Aquatic barriers to fish passage from the USFWS FPDSS⁽¹²⁾; major dams mapping by the USACE National Inventory of Dams⁽¹³⁾; NHD data on dams and divergence structures⁽⁶⁾; State data on water withdrawal locations (e.g. Michigan¹⁵)

Relative net water demand

Gauging station records, which may be used to develop natural flow estimators and calculate water demand relative to natural flow

Water use intensity

Gauging station records, which may be used to develop natural flow estimators and calculate water demand relative to natural flow

Biotic or climatic risks

Elevation (mean elevation of the watershed or specific stream segment)

USGS NED⁽⁶⁾; USGS EDNA⁽⁷⁾; NHDplus flowline elevation data⁽⁴⁾

Invasive species risk

USGS Non-Indigenous Aquatic Species Information Resource⁽¹⁶⁾; Non-Indigenous Species Database Network range maps⁽¹⁷⁾; USDA National Invasive Species Information Center⁽¹⁸⁾

Severity of pollutant loading

Number of 303(d) listed causes

ATTAINS⁽²⁰⁾

Number of permits

EPA's national geospatial dataset on permits

CSO or MS4 areas

Spatial data available at state and municipal level

Age of sewer infrastructure

Spatial data available at municipal level

Severity of loading (compares current loading with TMDL target loading calculation for percent reduction needed)

ATTAINS data on 303(d)-listed waters⁽²⁰⁾; loading estimates from TMDLs or watershed models (e.g., from EPA's website)⁽¹⁹⁾

Stressor persistence

Project specific

SPARROW nitrogen loading estimate

Water quality data from EPA's NPDAT website⁽²⁰⁾; regional modeling data from the USGS decision support system⁽²¹⁾

SPARROW phosphorus loading estimate

Water quality data from EPA's NPDAT website⁽¹⁹⁾; regional modeling data from the USGS decision support system⁽²⁰⁾

Watershed stream miles impaired

EPA ATTAINS data on 303(d)-listed waters⁽²⁰⁾

Watershed water body acres impaired

EPA ATTAINS data on 303(d)-listed waters⁽²⁰⁾

Modeled watershed aerial N deposition

N/A

Modeled watershed aerial Hg deposition

REMSAD; CMAQ; range of likely impacts from foreign sources⁽²²⁾

Other stressor-specific severity factors

Project-specific stressor data

Legacy of past, trajectory of future use

Land use change trajectory

NLCD 1992⁽³⁾; NLCD 2001⁽⁴⁾; NLCD 2006⁽⁵⁾; USGS Land Cover Trends Project⁽²³⁾; USGS Temporal Urban Mapping project⁽²⁴⁾; USGS Historical Topographic Map Collection⁽²⁵⁾

Legacy land uses

USGS Land Cover Institute⁽²⁶⁾; NLCD 1992⁽²⁷⁾; NLCD land use change between 2001 and 2006⁽³⁾; Historical Topographic Map Collection^(24_

Watershed percent legacy agriculture

USGS Land Cover Institute⁽²⁵⁾; NLCD 1992⁽²⁶⁾; NLCD land use change between 2001 and 2006⁽³⁾

Watershed percent legacy urban

USGS Land Cover Institute⁽²⁶⁾; NLCD 1992⁽²⁷⁾; NLCD land use change between 2001 and 2006⁽³⁾; Historical Topographic Map Collection⁽²⁴⁾

Corridor percent legacy agriculture

USGS Land Cover Institute⁽²⁵⁾; NLCD 1992⁽²⁶⁾; NLCD land use change between 2001 and 2006⁽³⁾

Corridor percent legacy urban

USGS Land Cover Institute⁽²⁶⁾; NLCD 1992⁽²⁷⁾; NLCD land use change between 2001 and 2006⁽³⁾; Historical Topographic Map Collection⁽²⁴⁾

Factor used in analysis

Data source(s)

ATtILA Landscape metrics

Total terrestrial area

NLCD⁽²⁹⁾

Percent cropland

Percent pasture

Percent all agricultural land use

Percent forest

Percent man-made barren

Percent natural barren

Percent natural grassland

Percent shrubland

Percent urban

Percent user-defined class

Percent wetland

Percent all natural land use

Percent all human land use

Percent agricultural cropland on slopes › 10%

NLCD⁽²⁷⁾; NED

Percent agricultural pasture on slopes › 10%

Percent any agricultural on slopes › 10%

ATtILA Riparian metrics

Percent stream length adjacent to agricultural land use

NLCD⁽²⁷⁾; NED

Percent stream length within 30m of agricultural land use

Percent stream length wthin 120m of agricultural land use

Percent stream length adjacent to cropland

Percent stream length within 30m of cropland

Percent stream length within 120m of cropland

Percent stream length adjacent to pasture

Percent stream length within 30m of pasture

Percent stream length within 120m of pasture

Percent stream length adjacent to urban land use

Percent stream length within 30m of urban land use

Percent stream length within 120m of urban land use

Percent stream length adjacent to human land use

Percent stream length within 30m of human land use

Percent stream length within 120m of human land use

Percent stream length adjacent to natural grassland

Percent stream length within 30m of natural grassland

Percent stream length within 120m of natural grassland

ATtILA Human stressor metrics

Density of 4-lane highways

TIGER 2000 (1:100,000)⁽²⁸⁾

Density of 2-lane highways

Density of interstate freeways

Length of roads within 30m of streams

TIGER 2000 (1:100,000)⁽³⁰⁾; NHD

Length of 4-lane highways within 30m of streams

Length of 2-lane highways within 30m of streams

Length of county, city roads within 30m of streams

Number of road/stream crossings

Number of 4-lane highway/stream crossings

Number of 2-lane highway/stream crossings

Number of county, city road/stream crossings

Nutrient loading

N/A

Phosphorus loading

N/A

Population density (population count/km 2)

N/A

Percent change in total population

N/A

Percent impervious cover

NLCD⁽²⁷⁾

ATtILA physical characteristic metrics

Area of wetland

NWI

Stream density

NHD

Topographic position of wetland

NED

Desktop GIS-derived metrics

Density of canals, ditches (km/km 2)

NHD

Density of wells (#/km 2)

N/A

Percent of land likely grazed by livestock

NLCD⁽²⁷⁾; BLM; ICBEMP

Pollutant discharge

EPA; ICBEMP

Railroads

TIGER 2000 (1:100,000)⁽²⁸⁾

Recreation access and navigation improvements

BLM; IDPR

Recent timber harvest

USGS; Northwest ReGAP project; NatureServe

Toxic element concentration

EPA; ICBEMP

Utility corridors

ICBEMP

Dairies

IDWR

Dams and reservoirs

IDWR; NHD

Dredge spoils or other solid waste disposal

EPA

Effluent discharge (from industrial or energy facility that alters thermal regime)

EPA

Groundwater pumping: ex-urban development

IDWR

Mining

IDL; USGS; IDEQ

Factor used in analysis

Data source(s)

North region

Percent agricultural land use

NLCD⁽²⁷⁾

Percent natural grassland

Percent cropland

Percent pasture

Percent urban

Percent stream length within 30m of urban land use

NHD; NLCD⁽²⁷⁾

Percent stream length within 30m of urban land use

Percent agricultural land use on slopes › 9%

NLCD⁽²⁷⁾; NED

Density of 4-lane highways

TIGER 2000 (1:100,000)⁽²⁸⁾

Density of 2-lane highways

Length of 4-lane highways within 30m of streams

TIGER 2000 (1:100,000)⁽²⁸⁾; NHD

Length of 2-lane highways within 30m of streams

Number of 4-lane highway/stream crossings

Number of 2-lane highway/stream crossings

Nitrogen loading

N/A

Phosphorus loading

N/A

Population density

N/A

Density of wells (#/km 2)

N/A

Percent likely grazed by livestock

NLCD; BLM; ICBEMP

Index of environmental vulnerability

Mean elevation

NED (30m)

Mean precipitation

UM NTSG total precipitation data (1980-1997, 18-year mean, 1 km resolution)⁽³¹⁾

Mean slope

NED (30m)

Percent forest

2001 NLCD

Percent stream length adjacent to natural land

Streamnet (IDFG 2008, 1:100,000)

Percent stream length within 30m of natural land

Streamnet (IDFG 2008, 1:100,000)

South region

Percent agricultural land use

NLCD⁽²⁷⁾

Percent cropland

Percent pasture

Percent urban

Percent human land use

Percent stream length adjacent to agricultural land use

NLCD⁽²⁷⁾; NHD

Percent stream length within 30m of agricultural land use

Percent stream length within 120m of agricultural land use

Percent stream length adjacent to cropland

Percent stream length within 30m of cropland

Percent stream length within 120m of cropland

Percent stream length adjacent to pasture

Percent stream length within 30m of pasture

Percent stream length within 120m of pasture

Percent stream length adjacent to pasture

Percent stream length adjacent to urban land use

Percent stream length within 30m of urban land use

Percent stream length within 120m of urban land use

Percent stream length adjacent to human land use

Percent stream length within 30m of human land use

Percent stream length within 120m of human land use

Percent stream length adjacent to natural grassland

Percent stream length within 30m of natural grassland

Percent stream length within 120m of natural grassland

Density of interstate freeways

TIGER 2000 (1:100,000)⁽²⁸⁾

Length of roads within 30m streams

TIGER 2000 (1:100,000)⁽²⁸⁾; NHD

Length of county, city roads within 30m of streams

Number of road/stream crossings

Number of county, city road/stream crossings

Nitrogen loading

N/A

Phosphorus loading

N/A

Area of wetland

NWI

Stream density

NHD

Density of canals, ditches (km/km 2)

NHD

Density of wells (#/km 2)

N/A

Percent likely grazed by livestock

BLM; ICBEMP; NLCD⁽²⁷⁾

Index of environmental vulnerability

Mean elevation

NED (30m)

Mean precipitation

UM NTSG total precipitation data (1980-1997, 18-year mean, 1 km resolution)

Mean slope

NED (30m)

Area of wetland

NWI

Stream density

Streamnet (IDFG 2008, 1:100,000)

Factor used in analysis

Data source(s)

Roads

4-wheel drive

2001 TIGER/US Census Bureau

Local roads, city streets

Highways

Land cover

Urban

2001 NLCD

Crop agriculture

Timber harvest

Hydrology

Artificial flow

2007 NHD

Water rights point-of-use

MTDNRC

Section 404 permits

MTNRIS

Resource extraction

Abandoned mines

MTDEQ

Oil or gas extraction

MTNRIS

Factor in the analysis

Data source(s)

Land cover and road impacts

Percent developed land

National Land Cover Dataset

Road density

StreetMap USA (Esri & Tele Atlas)

Density of road/stream crossings

StreetMap USA and National Hydrography Dataset

Dam and drinking water supply impacts

Dam density

EPA

Dam storage capacity

EPA

Drinking water supply density

EPA

Point source impacts

Point source density

EPA

Factor in the analysis

Data source

Percent developed land

NLCD

Percent agricultural land

NLCD

Total road density per watershed area

StreetMap USA

Factor used in analysis

Data source

Watersheds around each wetland

USGS National Elevation Dataset

Wetlands

NWI

Density of roads within 200m of each wetland

US Census TIGER/Line roads (2000)

Land cover data

NLCD

Factor used in analysis

Data source(s)

Condition of nearest stream (0 = excavated, 1 = natural)

NWI stream and ditch map

Percent cropland and grassland within 100m

2001 NWI

Percent developed land within 1000m

2001 NWI

Percent mixed forest within 1000m

2001 NWI

Distance to nearest stream (m)

1:24,000 NHD

Percent pixels with zero impervious cover within 100m

2001 NLCD

Distance to nearest road (m)

Census TIGER data⁽³⁶⁾

Percent wetland within 100m

Wetlands from NWI and states of MD and DE

Percent forest within 100m

2001 NLCD

Percent wooded wetland within 1000m

2001 NLCD