NEWSLETTER

Chesapeake Assessment Scenario Tool

CAST Newsletter: October 2025

Tips and information to facilitate environmental restoration efforts in the Chesapeake Bay watershed

Did You Know?

Did you know BMP Targeting Maps are available to help identify where conservation practices will have the greatest impact? Using CAST delivery factors and 2024 Progress loads, these maps highlight model segments most effective for BMP placement. Delivery factors show how nutrients and sediment move from land to water--higher values mean greater potential runoff. Six bivariate maps display this relationship by nutrient and sector, with darker areas indicating where BMPs can deliver the most benefit. Explore the maps using the button on the Map Tools & Spatial Data page, or download the shapefiles directly to your computer. To learn more, check out the presentation "Explaining Changes in Nitrogen and Phosphorus Loads Using Land Management Practice Data."

CAST Webinars and Training

Upcoming Webinars

Join us for Watershed Planning with CAST: Aligning Local Actions to the Revised Chesapeake Bay Agreement to learn how to use CAST to develop watershed plans that reflect the Bay Agreement's updated goals. This session will highlight what's new in the Agreement, demonstrate CAST's planning tools, and show how to prioritize actions that deliver both nutrient reductions and community co-benefits.

  • Topic: Watershed Planning with CAST: Aligning Local Actions to the Revised Chesapeake Bay Agreement
  • Time: October 16, 2025 at noon EDT
  • Join Zoom Meeting
  • Meeting ID: 868 4886 3846
  • One tap mobile +13017158592,,86848863846#

Join us for a conversation with Scott Raubenstine, Vice President of Agricultural Services at Perdue AgriBusiness, as we explore how modern farming practices, evolving consumer expectations, and watershed health intersect.

Scott will share how Perdue is working with farmers, partners, and conservation organizations to advance practical, science-based solutions that support both agricultural productivity and environmental stewardship. He'll highlight the company's ongoing work in areas such as regenerative agriculture, water quality, and soil health, as well as broader efforts related to sustainable food production and responsible sourcing.

The session will also feature a demonstration of how CAST can model real-world best management practices (BMPs) to identify the most effective and cost-efficient strategies for reducing nutrient and sediment runoff--supporting shared goals for farm viability and Bay restoration.

  • Topic: Aligning Corporate Sustainability and Chesapeake Bay Restoration Goals
  • Time: November 20, 2025 at noon EST
  • Join Zoom Meeting
  • Meeting ID: 838 6405 5580
  • One tap mobile +13017158592,,83864055580#

In-person trainings are available upon request.

Available Training Videos

September's CAST webinar featured guest presenter Marcie Dunn, who shared her experience using NRCS planning tools--Conservation Desktop and the Conservation Assessment and Ranking Tool (CART)--to identify, prioritize, and evaluate on-farm conservation practices. Marcie walked through a real-world project example to show how these tools support decision-making and demonstrate the benefits of conservation efforts at the farm scale. Following Marcie's presentation, we introduced the Farm Scale Pollutant Load Analysis Field Guide as an alternative approach that anyone can use with publicly available CAST data to estimate both water quality and carbon reduction benefits of BMPs.

This, and other past training videos on topics ranging from buffers to targeting nutrient reductions, are available in the Learning section of CAST under 'Free Training Videos'. Amongst the variety of training content available, there are also short videos on topics like 'Where do I start,' under Additional Resources.

Chesapeake Bay Watershed Success Story

A Tunnel Worth Cheering-Alexandria Wins National Award: River Renew's $615 million sewer tunnel project honored nationally for innovation, teamwork, and clean water benefits. Read more about this success story on The Zebra's website.

Does your organization have a Chesapeake Bay Watershed success story you'd like to share? If you have a story you would like to see in the next CAST Newsletter, submit an article using the 'Contact Us' feature from any page of the CAST website.

Chesapeake Bay Program Deadlines

Progress toward the Bay TMDL

The Chesapeake Bay Deadlines refer to the major jurisdictions' annual reporting of new BMPs implemented, and existing BMPs verified as functioning in the watershed. BMP implementation information is used to create annual progress scenarios using CAST and to make assessments and report out the estimated impacts of restoration efforts.

  • No later than December 1, 2025: Final BMP submissions for previous July 1 - June 30 data period due from jurisdictions for the 2025 Progress Phase 6 model assessment - both wastewater data and non-wastewater BMPs. Wastewater data includes the categories CSO, bio-solids, spray irrigation, large onsite septic systems, and rapid infiltration.
  • December 2025: Progress reports and resubmission reminders are available each Friday. Calls with state technical leads are scheduled to resolve issues.
  • January 2026: Progress reports and resubmission reminders continue. Calls with state technical leads continue.
  • February 6, 2026: Final opportunity for states to update BMP data.
  • February 9, 2026: Final progress run information available to jurisdictions - needed for outside reporting of progress on commitments to keep results relevant.
  • May 8, 2026: 2025 Progress finalized and released on CAST. Progress may be delayed due to unresolved issues surrounding the verification assessments.

Updates to CAST

New features:

The manure transport BMP logic now allows manure to be transported into areas where there are no animals and no crops. Previously, that manure was not counted in the area.

Security updates were made.

This update affects the loads in the 2024 Progress scenario in Charlottesville and Alexandria, Virginia.

A full list of changes is available on CAST's Upgrade History. The new CAST version is Phase 6 - 7.14.3.

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