City Engineers Association of Minnesota



Are Your Ponds Serving their Water Quality Function?

Thursday, June 1, 2023 from 12:00pm – 1:00pm CDT

Featuring Poornima Natarajan and John Gulliver


Stormwater ponds and wetlands across a wide variety of characteristics (e.g., watershed history, age, size, depth, aquatic vegetation) are used to treat stormwater to remove a significant portion of sediment and associated pollutants in runoff (e.g., phosphorus, nitrogen, hydrocarbons, and metals) prior to the runoff being released downstream. An important contemporary management issue is that some stormwater ponds appear to be less effective than expected or originally intended in phosphorus retention, a key function of these stormwater best management practices (BMPs) in urban environments. Retention of phosphorus is critical because phosphate, a dissolved form of phosphorus, sustains algal and cyanobacteria growth and causes a wide range of water quality impairments in the ponds and downstream waters including algal blooms, excess floating plants, taste, and odor problems.

Learning Objectives

  • A Pond Assessment Tool, was developed to identify and evaluate ponds at risk for poor phosphorus water quality and export of phosphorus to receiving water bodies. It results from data analysis of 230 water bodies and detailed water quality and sediment analysis of 20 ponds, which formed the basis of the Pond Assessment Tool tool with statistical analysis of field data and regression models for predicting pond TP, pond anoxia, and sediment release. 
  • Recommendations for stormwater pond maintenance and wetland management based on project results and data synthesis of construction and maintenance costs and runoff storage/settling alternatives.
    Poornima Natarajan

    Poornima Natarajan

    St. Anthony Falls Laboratory Research Associate, University of Minnesota

    John S. Gulliver

    John S. Gulliver

    Professor Emeritus, University of Minnesota

    John S. Gulliver is a professor emeritus in the Department of Civil, Environmental and Geo- Engineering and a resident fellow at the Institute on the Environment. Gulliver has taught courses in fluid mechanics, environmental mass transport, and urban hydrology and water quality.  Poornima Natarajan is a Research Associate at the St. Anthony Falls Laboratory, with research interests focused on stormwater management and treatment She received her Ph. D. from the University of Maryland in 2012.

    Since 2016, Dr. Gulliver, Dr. Natarajan and co-investigators have been studying phosphorus release from pond sediments resulting from low dissolved oxygen concentrations in the bottom of the pond caused by pond thermal and chemical stratification. They first identified shallow stratification and low bottom-water dissolved oxygen as the cause of high phosphorus concentration in some ponds and began a field campaign to identify the ponds that were releasing phosphorus from the sediments and develop a rationale for these events. After multiple years of pond in situ measurements of temperature, dissolved oxygen and conductivity profiles in the ponds; sediment characterization and release rate studies and field weather measurements in 21 ponds, they used the information to develop a Pond Assessment Tool to assess the likelihood of low dissolved oxygen concentration, high phosphorus concentration in the pond, and phosphorus release from the sediments in Minnesota ponds. They also developed a numerical model of pond stratification and water chemistry, linked with a three-dimensional wind model to investigate the efficacy of six pond phosphorus remediation techniques.

    2023 CEAM Summer Meeting

    Wednesday, August, 9, 2023

    Please join us for the CEAM Business Meeting at 11:00 AM at League of

    Minnesota Cities, followed by a Saints Game in Saint Paul at 1:00 PM.


    Image of DoubleTree hotel


    January 31-February 2, 2024

    Join us at the Double Tree in Bloomington for opportunities to see how other cities are using new technologies and developing innovative construction projects, as well as a chance to network with other professionals and peers.

    DoubleTree by Hilton Hotel Bloomington
    7800 Normandale Blvd, Bloomington, MN 55439


    Click on the button to view presenter materials, session information, and more from our 2023 CEAM Annual Conference.


     Get updated on future events and connect with other members of CEAM by joining our private LinkedIn group:

    About Fusion Learning Partners

    From learning opportunities and events to organizational development and collaborative initiatives, Fusion exists to strengthen and transform the communities where we work, live, and thrive.

    Because Innovation Begins with Learning.

    2024 Planning Committee

    Jen Desrude, President, City of Burnsville
    Mark DuChene, Co-Chair, City of Faribault
    Eric Seaburg, Co-Chair, Bolton & Menk, Inc.
    Greg Anderson, Short Elliot Hendrickson, Inc.
    George Bender, City of Chanhassen
    Dan Boyum, Stantec
    Dan Coyle, Kimley-Horn & Associates
    Marc Culver, Bolton & Menk, Inc.
    Steve Dodge, City of Inver Grove Heights
    Jennifer Edison, WSB & Associates
    Justin Femrite, City of Elk River
    Jack Griffin, FOCUS Engineering, Inc.
    Matt Hansen, SRF Consulting Group, Inc.
    Debra Heiser, City of St. Louis Park
    Jeff Johnson, City of Mankato
    Janna Kieffer, Barr Engineering
    Tony Kutzke, City of Woodbury

    Will Manchester, City of Minnetonka
    Amy Marohn, City of Bloomington
    Bob Moberg, 3PM Solutions
    Randy Newton, City of St. Paul
    Michael Payne, City of Plymouth
    John Powell, City of Farmington
    Steven Prusak, SRF Consulting Group, Inc.
    Joseph Rhein, Bolton & Menk, Inc.
    Paul Sandy, WSB & Associates
    Ted Schoenecker, MnDOT – State Aid
    Chad Setterholm, Short Elliot Hendrickson, Inc.
    Bob Simons, City of Bloomington
    Brandon Stenglein, City of Maple Grove
    Jim Studenski, TKDA
    Michael Thompson, City of Plymouth
    Anjela Tomovic, MnDOT – State Aid
    Steve Winter, MSA Professional Services