Updates to the Acquisition of DART's Columbia Basin Hydrology Data

Historically, DART retrieved hourly and daily hydrology data from multiple sources published by USACE and PUDs to ensure timeliness and eliminate gaps in the data stream. This resulted in timestamping issues that eroded the utility of DART's hourly hydrology datasets. DART has revamped the acquisition of the hourly and daily hydrology data to resolve these timestamping issues. Now, DART's Columbia Basin hydrology time-series data are retrieved from the USACE CROHMS Dataquery 2.0 (DQ2) website with "PST" settings. This update provides a standardized source for historical and real-time data with consistent timestamping for hourly data, improving its utility for use in modeling and elucidating daylight savings transitions. Upper and lower bounds of data parameter values have been added to eliminate extreme outliers.

DQ2 itself has significant missing and erroneous data. We used DART's original historical records of Columbia Basin daily and hourly hydrology to repair these QA/QC issues, if possible. DART continues to use alternative sources, such as the CROHMS ftppub website, where DQ2 data gaps continue to be present in real-time data, (e.g., RIS & RRH barometric pressure, CWMW & HGHM data, and scroll case water temperatures). Timestamping is adjusted to match the DQ2 "PST" for these alternative sources.

All web-based hydrology data results are reported in US/Pacific "clock" time.

Please contact the DART Team dart@cbr.washington.edu for more information. -- implemented 15 June 2022

1. Click on the data inventory icon to view the DART River Environment Data Inventory for All Parameters and All Years. This information is displayed in a new browser window.
2. Click on the project name to view additional information about that project, including operating agency, construction dates, DART datasets, and project photo. This information is displayed in a new browser window.

USACE Data Disclaimer: These data are furnished with the understanding that the Corps of Engineers makes no warranties concerning the accuracy, reliability, or suitability of the data for any particular purpose.

Inflow, Outflow, Spill, and Temperature (Scroll Case) data are collected at the project (dam). Spill Percent is calculated by DART from the Outflow and Spill values. Temperature (WQM), Barometric Pressure, Dissolved Gas and Dissolved Gas Percent are measured at Water Quality Monitoring stations in the forebay and tailrace of most projects and other key locations in the basin (prior to 1995, these data are from a variety of sources within the U.S. Army Corps of Engineers). Turbidity is measured in the forebay or in the fish ladders at a project. Elevation is measured in the forebay and tailwater of a project.

Bonneville Dam, 18 July 2006: The USACE initially reported incorrect hourly Bonneville spillway discharge for 2002-2004. DART is reporting the USACE's Recalibrated Spillway Discharge at Bonneville for this period. The Water Quality reports for BON, CWMW, CCIW, and WRNO include the recalibrated spill at Bonneville.

Wells Dam, 13 August 2012: The DCPUD has requested the water temperature data reported as the "Wells Scrollcase Water Tempurature" obtained for DART from prepared USACE text files be removed as erroneous. The Wells project does not report scrollcase water temperatures. This data has been removed from the publicly accessible DART dataset.

June 5 - July 9, 2013: DART reported partial averages for outflow and spill from several Upper Columbia PUD projects. These values have been corrected to show the average of the complete day. We would like to thank the CCPUD for helping us correct this issue.

River Environment Glossary

Barometric Pressure

Barometric Pressure is atmospheric pressure at the site, given in mm Hg. It represents an average of hourly measures. Barometric Pressure is measured at Water Quality Monitoring stations in the forebay and tailrace of most projects (see Data Sites Map) and other key locations in the basin. Prior to 1995, the data are from a variety of sources within the U.S. Army Corps of Engineers.

Dissolved Gas

Dissolved gas is a measure of the pressure of dissolved gas in the water column. When spillway water plunges into the tailrace nitrogen is forced into the water at higher than normal levels. This condition, called supersaturation, occurs when dissolved gas pressure in the water actually exceeds the atmospheric pressure. The dissolved gas value represents a daily average of hourly meeasures within the range of 600-900 mmHg and is derived from U.S. Army Corps of Engineers gas monitoring efforts. Often collected at irregular intervals, this parameter may be missing values for one or more days, or reported values may be obviously incorrect. Dissolved Gas is measured at Water Quality Monitoring stations in the forebay and tailrace of most projects (see Data Sites Map) and other key locations in the basin. Prior to 1995, the data are from a variety of sources within the U.S. Army Corps of Engineers.

Dissolved Gas Percent

Gas percent reflects the degree of total dissolved gas supersaturation in the river at the given location. Gas percent is the daily mean of hourly observations. When gas pressure is exactly the same as the atmospheric pressure, the water is considered to be 100% saturated. If the gas pressure value is higher than atmospheric pressure, gas percent values rise above 100%. Daily averages are calculated from hourly values within the range of 90% to 200%. Gas percent data is often found to be quite noisy due to rapid fluctuations in spill volumes and atmospheric pressures. Dissolved Gas Percent is measured at Water Quality Monitoring stations in the forebay and tailrace of most projects (see Data Sites Map) and other key locations in the basin. Prior to 1995, the data are from a variety of sources within the U.S. Army Corps of Engineers.

Elevation

Elevation is given in feet above mean sea level and is a daily average of hourly measures. At most sites this will change less than a fraction of a foot over normal operations. Elevation is measured in the forebay of a project.

Elevation 10 Year Average

Daily average of elevation for a selected 10 year range. For each month and day, the data is summed for the selected 10 years and divided by the number of non-null data points available during that 10 year span.

Inflow

Inflow measurements represent the 24-hour average of hourly measures, reported by the U.S. Army Corps of Engineers. Inflow is given in kcfs, thousands of cubic feet per second.

Outflow

Outflow measurements represent the 24-hour average of hourly measures, reported by the U.S. Army Corps of Engineers. Outflow is given in kcfs, thousands of cubic feet per second. This represents the total outflow at any project, including spill and fish ladder flow.

Outflow 10 Year Average

Daily average of outflow for a selected 10 year range. For each month and day, the data is summed for the selected 10 years and divided by the number of non-null data points available during that 10 year span.

Spill

Spill also is given as a daily average of 24 hourly measures taken by the U.S. Army Corps of Engineers. It is also given in kcfs.

Spill 10 Year Average

Daily average of spill for a selected 10 year range. For each month and day, the data is summed for the selected 10 years and divided by the number of non-null data points available during that 10 year span.

Spill Percent

Spill Percent is calculated by DART from the daily averaged value for Spill divided by the daily averaged value for Outflow at a project.

Temperature (Scroll Case)

Temperature (Scroll Case) is water temperature in degrees Celsius. This data is measured at the scroll case (part of the powerhouse) at a project. If provided values are in Fahrenheit, they are converted to Celsius. Temperature records are typically not collected outside the salmon migration season, so they are not usually 365 days long. Values above 0 C and below 35 C are averaged for a daily value.

Temperature (Scroll Case) 10 Year Average

Daily average of scroll case temperature for a selected 10 year range. For each month and day, the data is summed for the selected 10 years and divided by the number of non-null data points available during that 10 year span.

Temperature (WQM)

Temperature (WQM) is water temperature in degrees Celsius. This data is measured at Water Quality Monitoring stations in the forebay and tailrace of most projects (see Data Sites Map) and other key locations in the basin. Forebay Temperature records are typically not collected outside the salmon migration season, so they are not usually 365 days long. Daily averages are calculated from hourly values above 0 C and below 35 C. Temperatures at water quality monitoring stations were not collected prior to 1995.

Temperature (WQM) 10 Year Average

Daily average of water quality monitor temperature for a selected 10 year range. For each month and day, the data is summed for the selected 10 years and divided by the number of non-null data points available during that 10 year span.

Temperature (WQM) 7DADM

Seven (7) Day Average Daily Maximum. For each day, the maximum hourly temperature value for that day and the previous six days are averaged. All 7 data points must be non-null or the calculated value for the day is null.

Temperature (WQM) 5DADA

Five (5) Day Average Daily Average. For each day, the daily average temperature value for that day and the previous four days are averaged. All 5 data points must be non-null or the calculated value for the day is null.

Turbidity

Turbidity measures the water clarity, and by inference, the amount of particulate matter present. Turbidity is measured in the forebay or in the fish ladders of a project. Turbidity is reported in feet and measured with a Secchi Disk. In general, the Secchi disk is a 20 cm circular black and white plate. The Secchi disk is attached to a calibrated line and lowered into the water to the depth at which it disappears. The disk is then lifted until it reappears. The arithmetic mean of the two depths is considered the Secchi disk transparency or limit of visibility.

Calculating 10 Year Averages

The 10 Year Averages are calculated by DART for each calendar day of data at each project. For the current year and any given project/month/day, the data from the previous 10 years on that calendar day is summed and divided by the number of non-null data points available. Calendar day averaging was chosen because, historically, data observations begin on a specific calendar day. Calendar day averaging gives different results than day of year averaging.