Status of Eyes on the Bay
Chesapeake Bay Program Data Submittals

Maryland Department of Natural Resources staff collect water quality data for a number of projects throughout Maryland. Data can include site information, water quality vertical profiles, light attenuation, weather conditions, comments, and laboratory analyses of parameters such as chlorophyll, nutrients and sediment. These data are submitted to the Environmental Protection Agency's Chesapeake Bay Program in monthly increments for each project. The table below shows the current status of each project's data collection, review and submission.

It does not include continuous data collected from water quality meters for Continuous Monitoring or Water Quality Mapping (DATAFLOW). Check their respective data pages on Eyes on the Bay for availability.

Current Year Data:

2025 Tidal Network Non-Tidal Network
Month Main Bay Tributary Continuous
Monitoring		 DataFlow BaseFlow StormFlow
January Completed In process In process Not collected Completed Completed
February Completed In process In process Not collected Completed Completed
March Completed In process In process Not collected Completed Completed
April Completed In process In process Not collected Completed Completed
May Completed In process In process Not collected Completed Completed
June Completed In process In process Not collected Completed Completed
July Completed In process In process Not collected Completed Completed
August Completed In process In process Not collected Completed Completed
September Completed In process In process Not collected Completed Completed
October Completed In process In process Not collected In process In process
November Completed In process In process Not collected In process In process
December Completed In process In process Not collected In process In process

Previous Year Data:

2024 Tidal Network Non-Tidal Network
Month Main Bay Tributary Continuous
Monitoring		 DataFlow BaseFlow StormFlow
January Completed Completed Completed Not collected Completed Completed
February Completed Completed Completed Not collected Completed Completed
March Completed Completed Completed Not collected Completed Completed
April Completed Completed Completed Not collected Completed Completed
May Completed Completed Completed Not collected Completed Completed
June Completed Completed Completed Not collected Completed Completed
July Completed Completed Completed Not collected Completed Completed
August Completed Completed Completed Not collected Completed Completed
September Completed Completed Completed Not collected Completed Completed
October Completed Completed Completed Not collected Completed Completed
November Completed Completed Completed Not collected Completed Completed
December Completed Completed Completed Not collected Completed Completed

Legend:
Completed: Sampling & data quality assurance (QA) complete. Data available on CBP DataHub. In process: Sampling or quality assurance (QA) protocol is in process.
Not conducted:
Sampling has not yet been conducted.		 Not collected: Sampling was not conducted either due to weather conditions or off-months.

CBP Data Status:

June 12, 2026 Update:

  • See the tables above for data that are in process or have been completed, submitted to the Chesapeake Bay Program (CBP), and a request to the CBP data manager has been made for acceptance and entry of the datasets into the CBP water quality database. There may be a lag period of several days before data are reviewed and posted by CBP. 
  • Please note that due to hardware and software updates, legacy data processing programs needed major programmatic updates which have largely been completed, allowing for data processing to resume in April 2025. 
  • Continuous monitoring datasets have been processed for June - March 2025 and are in review.
  • Dataflow was not conducted in 2024 but is being conducted in the Severn River for 2025
  • Tributary datasets have been processed for January - April 2025. January is ready for acceptance by CBP and February-April are in review.
  • Mainstem datasets have all been completed and submitted for 2025. Availability based on CBP data manager review, acceptance and upload to the datahub.
  • The 2025 water year (Oct 2024- September 2025) of Non-tidal Network baseflow and stormflow is near-complete. July-Sept. 2025 datasets are in final review and all other datasets are complete and submitted to CBP
  • Coastal Bays have been completed through 2024. 
  • Tidal laboratory results (tributary, continuous monitoring, main bay) from the CBL NASL lab have been received through April 2026. 
  • Chlorophyll data from the CBL NASL has been received through April 2026, and processed through February 2026.
  • Keypunched data has been received from MCE through December 2025. 

Tidal Network Projects:
Main Bay Long-term Fixed Monthly Monitoring profile sampling at discrete stations from a stationary boat in the Mainstem of the Chesapeake Bay.
Tributary Long-term Fixed Monthly Monitoring profile sampling at discrete stations from a stationary boat or bridge in Chesapeake Bay tributaries.
Continuous Monitoring Deployed in-situ water quality meter, coupled with bi-weekly on-site measurements and sampling (referred to as 'calibration data').
DataFlow Surface mapping program, sampling surface water from a moving boat.
 * More details on the above projects can also be found on our Data Types Overview page.

Non-Tidal Network:
BaseFlow Although called 'Baseflow' these routine samples are taken on a set monthly schedule over a range of flows, not just targeting low flow conditions.
StormFlow Along with Baseflow, Stormflow samples are collected at least once per quarter to account for seasonality, with a target of sampling 8 storms per year.