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Tools for Adaptive Management and Water Quality Trading

Statewide phosphorus multi-discharger variance

The following resources may assist you in developing adaptive management and water quality trading plans.

Guidance documents

Quantifying nonpoint source pollution loads and reductions

Nonpoint source pollution reductions are typically quantified through modeling.

Plans should recommend a quantification method if a model or tool is not listed, or if an alternative quantification method is preferred in lieu of the recommended model listed in guidance. Additional guidance available in the adaptive management handbook. Questions related to modeling may be submitted to Kevin Kirsch.

Calculation of pollutant reductions

  • Pollutant reductions from streambank stabilization projects should be calculated using site-specific measurements, soil test nutrient concentrations and the NRCS Erosion Estimator [XLSX].

Pollution Load Ratio Estimation Tool

The Pollutant Load Ratio Estimation Tool (PRESTO) is a statewide GIS-based tool that compares the average annual phosphorus loads originating from point and nonpoint sources within a watershed. This model is used to help determine adaptive management eligibility by quantifying the ratio of point to nonpoint sources in a watershed, and can also provide an indication of the potential for nonpoint trading credits within a watershed.

SPARROW Pollutant Delivery Model

The delivery factor accounts for the distance between trading partners and the impact that this distance has on the fate and transport of the traded pollutant in surface waters. In most cases, a delivery factor will not be necessary when the credit generator and credit user are both located in the same 12-digit hydrological unit (HUC-12) because of the negligible impacts of fate and transport at this scale.

The SPARROW model was developed by the United States Geological Survey (USGS) and relies on regression equations from monitoring data to create a delivery fraction between two points in a watershed. To help ensure water quality trades result in improved water quality, the SPARROW Model should be used for any trade involving credits generated outside of the credit user’s HUC-12 watershed.

Surface Water Data Viewer

The Surface Water Data Viewer is an interactive mapping tool that can identify impaired waterbodies and HUC-12 subwatersheds, and contains in-stream water quality monitoring data including phosphorus concentrations. Questions on this resource may be emailed to Surface Water Data Viewer Help.


Funding may be available to help finance portions of water quality trading projects. Clean Water Fund Loan Pilots can be used to finance trading plans for municipal discharges.


District Trading and Adaptive Management Coordinators [PDF] are available to provide technical assistance. County Land and Water Conservation staff may also partner to assist in development and implementation of adaptive management and/or trading. Visit Wisconsin Land and Water [exit DNR] to find County Conservation staff.

Reports of interest