Skip to Main Content


Dataflow instrument

The surface mapping program collects data every 4 seconds aboard a moving boat, using an instrument suite known as DATAFLOW. DATAFLOW uses a pump on the transom of the boat to feed surface water through a chamber where water quality is measured by a sonde/instrument similar to those used in the continuous monitoring program. The water quality data are geo-referenced with a GPS unit and recorded in an onboard computer. The boat follows a path that records surface water quality both in nearshore shallow areas and mid-channel areas of rivers and the Chesapeake. Data are used to assess water quality criteria, particularly the extent of acceptable habitat for underwater grasses. Data are also used to assess the scale of events such as algal blooms or runoff and pinpoint regions that require management action to improve water quality. For a more in-depth description of the DATAFLOW mapping program, click here.

DATAFLOW Data Download:
(2001 - 2023*)

Quality Assured DATAFLOW data have been through rigorous Quality Assurance and Quality Control. Download our DATAFLOW data directly based on sampling location and sampling date.
* Final, quality-assured data for the current year will be made available after the monitoring season, which ends in October.

  • Select a Sampling Location, then Choose Sampling Date(s):
    Please wait for sampling dates to load after highlighting a water body.
    Tributary/Water Body:
    (Select one only)
    Sampling Dates:
    Hold down CTRL-key to select up to 21 dates

    Check your download folder for your data file, filename: "EOTBDataflowData_TributaryName.csv".


DATAFLOW Data Integrated Surface Maps:

Use our DATAFLOW Map Query to view spatially interpolated maps of surface water quality data, based on a station(s) and date(s) of your choosing.

  • Select Water Bodies, then Choose Sampling Date(s)
    Hold down CTRL-key to select multiple tributaries or sampling dates
    Tributary/Water Body:
    Sampling Dates: