Estuaries Project

Linked Watershed-Embayment Model to Re-evaluate Critical Nitrogen Loading Thresholds for Stage Harbor/Oyster Pond, Sulphur Springs/Bucks Creek and Taylors Pond/Mill Creek Chatham, Massachusetts

FINAL REPORT – FEBRUARY 2007

Massachusetts Department of University of Massachusetts Dartmouth Environmental Protection School of Marine Science and Technology

Massachusetts Estuaries Project

Linked Watershed-Embayment Model to Re-evaluate Critical Nitrogen Loading Thresholds for Stage Harbor/Oyster Pond, Sulphur Springs/Bucks Creek and Taylors Pond/Mill Creek Chatham, Massachusetts

FINAL REPORT – FEBRUARY 2007

Brian Howes Roland Samimy David Schlezinger

Sean Kelley John Ramsey

Ed Eichner

Contributors: US Geological Survey Don Walters and John Masterson

Applied Coastal Research and Engineering, Inc. Elizabeth Hunt

SMAST Coastal Systems Program Jennifer Benson, Michael Bartlett, Sara Sampieri

Cape Cod Commission Kiaotong Wu

MASSACHUSETTS ESTUARIES PROJECT

Preface and Acknowledgements

This current re-evaluation of the nitrogen thresholds for the three south side Chatham embayments represents the fifth product in a series of deliverables developed under the overall Massachusetts Estuaries Project nutrient evaluation for the Town of Chatham that got underway in 2002 (building upon an earlier effort by ACRE/ASA/SMAST 2000). The present effort was undertaken by the MEP Technical Team to assist the Town of Chatham in its CWMP for the restoration of its estuaries. The MEP Technical Team received no support from MassDEP for updating the water-use/land-use database and the re-calibration of the MEP Linked Models presented herein. However, as the updating of these models is critical to making management decisions relative to these estuaries, the MEP Technical Team and the Town of Chatham performed this update. Critical MEP documents that preceded this specific evaluation include:

1) MEP Linked Watershed-Embayment Model to Determine Critical Nitrogen Thresholds for Stage Harbor, Sulphur Springs, Taylors Pond, Bassing Harbor and Muddy Creek, Chatham, Massachusetts (FINAL - December 2003) 2) MEP linked Watershed-Embayment Model to Determine Critical NitrogenThresholds for the Pleasant System, Orleans, Chatham, Brewster, and Harwich, Massachusetts (FINAL – May 2006) 3) MEP Technical Memorandum: Muddy Creek Scenario Analyses (FINAL – August 2006 4) MEP Technical Memorandum: Cockle Salt Marsh Nitrogen Threshold (DRAFT – May 2006, FINAL – November 2006)

The Massachusetts Estuaries Project Technical Team would like to acknowledge the contributions of the many individuals who have worked tirelessly for the restoration and protection of the critical coastal resources within the Town of Chatham. Without these stewards and their efforts, this project would not have been possible.

First and foremost is the significant time and effort in data collection and discussion spent by members of the Chatham Technical and Citizens Advisory Committees, and particularly the contributions of Dr. Bob Duncanson, Bill Redfield, Margaret Swanson, Ted Keon, Fred Jensen, and John Payson. Similarly, critical data to support this assessment and synthesis was provided by the citizens who have generously given of their time to collect the needed nutrient samples over the past 7 summers through the Chatham WaterWatchers and the Town of Chatham Water Quality Monitoring Program. In addition, the Chatham Water Quality Laboratory has collaborated in the sample collection for a variety of sub-projects, needed to address site-specific nitrogen issues..

In addition to local contributions, we are also thankful for the long hours in the field and laboratory spent by SMAST staff (Dr. David White, Elizabeth White), Nat Donkin, interns and students within the Coastal Systems Program