The United States Geological Survey Virginia and West Virginia Water Science Center (USGS VA-WV-WSC) and Fairfax County assembled this data release in support of ongoing USGS VA-WV-WSC monitoring and evaluations of stream conditions overtime of two previously restored, urban-suburban streams in Reston, Virginia – Snakeden Branch and The Glade. The aquatic benthic macroinvertebrate, fish, and habitat sampling and surveying were conducted on the same eight, 100-meter stream reaches (four reaches in Snakeden Branch and four reaches in The Glade) by the USGS VA-WV-WSC. Aquatic benthic macroinvertebrate sampling and physical habitat surveys were conducted in both Spring and Fall of 2021 and a fish survey was conducted in the Summer 2021. Data provided are of five general types: 1. Site locations and characteristics for each of the eight sampling and surveying sites within the two monitored streams; 2. Benthic macroinvertebrate identifications and analytical laboratory results; 3. Fairfax County benthic macroinvertebrate Index of Biotic Integrity (IBI) scores and individual metric results; 4. Fish assemblages, and; 5. Physical habitat measurements. The metadata file “Metadata_for_Reston_Ecological_Data.xml” contains important information pertaining to the attributes of each entity of data, field and laboratory methods, and caveats associated with the Fall benthic macroinvertebrate IBI and metric scores. The "README.txt" file contains a description of each file contained in this data release. This database contains the aquatic benthic macroinvertebrate taxonomic identification and abundance data derived from samples collected at each of the eight total reaches within Snakeden Branch and The Glade in Fall and Spring of calendar year 2021. Samples were collected by the USGS VA-WV-WSC using the Fairfax County standard operating procedures (FCSOP) and specimen identification and abundance calculations were performed by a third-party laboratory. Fairfax County benthic macroinvertebrate IBI scores and individual metrics were calculated by Fairfax County following FCSOP. It is important to note for this data release that the IBI scores presented for Fall samples have caveats associated with them and the ratings (e.g. Excellent, Good, Fair, etc.) for the Fall samples have been intentionally excluded. Please read the methods section of the “Metadata_for_Reston_Ecological_Data.xml” file carefully for further explanation. This data release also contains the fish assemblages data, collected during the Summer of 2021, from the eight total reaches in Snakeden Branch and The Glade. Electrofishing surveys were conducted following FCSOP by the USGS VA-WV-WSC to obtain these results. Finally, this data release contains the physical habitat data surveyed in both Fall and Spring of 2021. Multiple habitat metrics were measured throughout each of the eight total reaches on Snakeden Branch and The Glade.

This dataset provides analysis results for recent status of and trends in 44 fish and 99 macroinvertebrate assemblages in the Chesapeake Bay watershed. For both biological datasets a multi-metric index, metric of assemblage sensitivity, functional feeding group metric and habitat preference metric was selected for analysis. Sites used to calculate trends required a minimum of 7 years of data. Status was calculated as a three-year average by averaging metric values for the most recent three years of data at each site and trends were calculated using generalized additive models (GAM) in the R package 'mgcv' for the full window of sample years at each site. Detailed data preparation information, analytical methods, and results are presented and discussed in the associated Scientific Investigative Report (https://doi.org/10.3133/sir20255072).

Data provided from the Virginia Department of Environmental Quality (DEQ) including simulated values of 72 hydrologic metrics, or indicators of hydrologic alteration (IHA), 37 fish metrics, and 64 benthic invertebrate metrics were reviewed to assess significant flow-ecology relations that may be developed. Hydrologic alteration was represented by simulation of streamflow record for a pre-water-withdrawal condition (baseline) without dams or developed land, compared to the simulated recent-flow condition (2008) including withdrawals, dams and altered landscape to calculate a percent-alteration of flow. Biological samples used represent a median condition of the biological community from 1972 to 2010. This study reviewed more than 7,272 linear regression models that relate altered flow conditions to biological sample metrics in Virginia. Decreasing flow conditions were the focus of this evaluation because of their relevance to the water-supply permitting process. The data tables highlight relations which may be significant and useful in future study and were further explored in the companion report; and relations that do not meet basic assumptions for valid linear regressions which were noted and omitted from the companion report. The three regions in Virginia defined by major drainage and physiographic boundaries as the Ohio River Drainages, Atlantic non-Coastal Plain, and Atlantic Coastal Plain were evaluated as well as a statewide grouping for fish and benthic data. This extensive dataset provided the opportunity for hypothesis testing and prioritization of flow-ecology relations that have the potential to explain the effect(s) hydrologic alteration has on biological metrics in Virginia.

Data provided from the Virginia Department of Environmental Quality (DEQ) including simulated values of 72 hydrologic metrics, or indicators of hydrologic alteration (IHA), 37 fish metrics, and 64 benthic invertebrate metrics were reviewed to assess significant flow-ecology relations that may be developed. Hydrologic alteration was represented by simulation of streamflow record for a pre-water-withdrawal condition (baseline) without dams or developed land, compared to the simulated recent-flow condition (2008) including withdrawals, dams and altered landscape to calculate a percent-alteration of flow. Biological samples used represent a median condition of the biological community from 1972 to 2010. This study reviewed more than 7,272 linear regression models that relate altered flow conditions to biological sample metrics in Virginia. Decreasing flow conditions were the focus of this evaluation because of their relevance to the water-supply permitting process. The data tables highlight relations which may be significant and useful in future study and were further explored in the companion report; and relations that do not meet basic assumptions for valid linear regressions which were noted and omitted from the companion report. The three regions in Virginia defined by major drainage and physiographic boundaries as the Ohio River Drainages, Atlantic non-Coastal Plain, and Atlantic Coastal Plain were evaluated as well as a statewide grouping for fish and benthic data. This extensive dataset provided the opportunity for hypothesis testing and prioritization of flow-ecology relations that have the potential to explain the effect(s) hydrologic alteration has on biological metrics in Virginia.

This data release links benthic macroinvertebrate sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks, hereafter referred to as V2 and HR, using the hydrolink methodology. Linked benthic macroinvertebrate sites are those included in the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) developed by the Interstate Commission on the Potomac River Basin (ICPRB) and available from the Chesapeake Bay Program (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.

This data release links benthic macroinvertebrate sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks, hereafter referred to as V2 and HR, using the hydrolink methodology. Linked benthic macroinvertebrate sites are those included in the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) developed by the Interstate Commission on the Potomac River Basin (ICPRB) and available from the Chesapeake Bay Program (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.

This data release links fish survey data from a suite of programs in the Chesapeake Bay watershed as well the benthic macroinvertebrate sites included in the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) developed by the Interstate Commission on the Potomac River Basin (ICPRB) and available from the Chesapeake Bay Program (https://datahub.chesapeakebay.net/LivingResources). The data set contains site name, survey program, coordinates of sample, and ancillary information such as sample date and site location information where available. It also includes the NHDPlus V2.1 unique identifier, COMID, as well as a confidence classification category for each of these assignments based on a set of pre-determined rules. In total there were 15 confidence categories ranging from high confidence to low confidence. We caution the use of sampling points which were given anything other than "high" confidence in their assignment to a given NHD catchment/flowline to avoid spurious/inappropriate attribution of geospatial data to benthic macroinvertebrate and fish data samples represented herein and refer the potential user to the Confidence Dictionary.csv which describes the criteria for each confidence category.

This data release links fish survey data from a suite of programs in the Chesapeake Bay watershed as well the benthic macroinvertebrate sites included in the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) developed by the Interstate Commission on the Potomac River Basin (ICPRB) and available from the Chesapeake Bay Program (https://datahub.chesapeakebay.net/LivingResources). The data set contains site name, survey program, coordinates of sample, and ancillary information such as sample date and site location information where available. It also includes the NHDPlus V2.1 unique identifier, COMID, as well as a confidence classification category for each of these assignments based on a set of pre-determined rules. In total there were 15 confidence categories ranging from high confidence to low confidence. We caution the use of sampling points which were given anything other than "high" confidence in their assignment to a given NHD catchment/flowline to avoid spurious/inappropriate attribution of geospatial data to benthic macroinvertebrate and fish data samples represented herein and refer the potential user to the Confidence Dictionary.csv which describes the criteria for each confidence category.

Montgomery County, Maryland Department of Environmental Protection has collected datasets to assess the health of streams since the early 1990s. Datasets include geomorphic stream cross-sectional surveys, fish and benthic macroinvertebrate counts and taxa abundance, and water chemistry data collected at the time of benthic and fish sampling (dissolved oxygen, pH, specific conductance, air temperature, and water temperature). Data span years 1992 to 2020 at five watersheds within the Clarksburg study area. Watersheds include a forested reference site (Soper), an urban site with centralized stormwater management (Crystal Rock), and three treatment watersheds (TR104, TR109, and Cabin Branch) within the Clarksburg Special Protection Area that transitioned from agriculture to suburban development with distributed stormwater management. These data were used to assess the impacts of distributed stormwater management on stream ecosystem function. All datasets were collected by Montgomery County, Maryland Department of Environmental Protection.

Montgomery County, Maryland Department of Environmental Protection has collected datasets to assess the health of streams since the early 1990s. Datasets include geomorphic stream cross-sectional surveys, fish and benthic macroinvertebrate counts and taxa abundance, and water chemistry data collected at the time of benthic and fish sampling (dissolved oxygen, pH, specific conductance, air temperature, and water temperature). Data span years 1992 to 2020 at five watersheds within the Clarksburg study area. Watersheds include a forested reference site (Soper), an urban site with centralized stormwater management (Crystal Rock), and three treatment watersheds (TR104, TR109, and Cabin Branch) within the Clarksburg Special Protection Area that transitioned from agriculture to suburban development with distributed stormwater management. These data were used to assess the impacts of distributed stormwater management on stream ecosystem function. All datasets were collected by Montgomery County, Maryland Department of Environmental Protection.