Potatuck IFIM

Project Name: Pootatuck River Water Withdrawal

Summary: Flow study helps balance resource use and habitat needs

Client: Potatook Land Company

Project Location: Newtown, CT

Services Provided:

•  Instream Flow Incremental
    Methodology Study

Project Timeframe: 2002 - 2004

Relationship with Client: Since 2004

Client Needs:
The Potatuck Land Company (Land Company) has privately managed a high quality harvestable trout fishery in the Pootatuck River in Newtown, Connecticut for over 100 years. The town of Newtown proposed to withdraw water from the Pootatuck River to supply new municipal and commercial developments within the town. The Land Company was concerned that withdrawal thresholds needed to be established so that the proposed water withdrawal would not impair the trout fishery.
Kleinschmidt Solution:
Kleinschmidt performed an Instream Flow Incremental Methodology (IFIM) study to develop quantitative habitat-discharge relationships in the river for brown, rainbow and brook trout. Trout habitat suitability was quantitatively modeled using a Physical Habitat Simulation (PHABSIM) model. Monthly unregulated flow for the study area was estimated in order to determine the duration and frequency of flows that might affect habitat suitability under natural vs. altered hydrologic conditions. Model results compared favorably with independently-derived “Connecticut ABF” estimates developed at Yale University. The Land Company and Newtown collaboratively reviewed study results to determine the feasibility and operational limits for the proposed water withdrawal.
Client Benefits:
The parties successfully negotiated a water withdrawal plan in a timely manner that met both the town’s needs and protected the trout resource.