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Yahara WINS Watershed Carbon Project

Regen Registry • Madison Metropolitan Sewerage District
73K+
Tonnes CO₂e Avoided
139K
Hectares
24,143
First Credits Issued
20 yr
Crediting Period
Program Overview

Watershed Carbon for Wisconsin

On January 16, 2026, the Madison Metropolitan Sewerage District announced the first issuance of 24,143 verified carbon credits under a new Regen Registry methodology for watershed-based infrastructure alternatives—a milestone for the intersection of water quality and climate finance.

Rather than constructing energy-intensive treatment systems costing $78–$124 million, the District implemented the Yahara WINS (Watershed Improvement Network) program across 139,000 hectares of the Yahara Watershed in Wisconsin. The initiative unites municipalities, conservation groups, and farmers to deploy field-level practices like cover crops, wetland restoration, and reduced tillage that cut phosphorus runoff while avoiding greenhouse gas emissions.

Over a 20-year crediting period (2017–2036), the project is projected to avoid approximately 73,463 tonnes of CO₂e. This demonstrates how utilities can achieve Clean Water Act compliance while generating verified climate benefits—creating a replicable model for other US water systems seeking climate-aligned regulatory approaches.

Why Watershed Carbon?

Traditional phosphorus reduction requires energy-intensive treatment upgrades. The Yahara WINS approach instead deploys regenerative agricultural practices across the watershed—cover crops, wetland restoration, riparian buffers—that reduce phosphorus runoff at a fraction of the cost while simultaneously avoiding CO₂ emissions.

Carbon credit revenue creates a sustainable funding mechanism that reduces the cost burden on ratepayers while supporting long-term ecological benefits for the watershed.

Partners

Madison Metropolitan Sewerage District Regen Registry Dane County Yahara Pride Farms Water Environment Federation M.A. Mortenson Companies
“Carbon finance has finally reached a point where it can meaningfully reduce the cost burden on ratepayers while supporting long-term ecological benefits.”
— Martye Griffin, Ecosystem Services Manager, Madison Metropolitan Sewerage District
Program Timeline

Key Milestones

2012

Pilot Launch

Yahara WINS launched as a four-year pilot project to test watershed adaptive management as an alternative to traditional treatment upgrades.

2017

Full-Scale Implementation

Transitioned from pilot to full 20-year implementation across the 536 square mile Yahara Watershed, engaging 30+ municipal stakeholders.

January 2026

First Carbon Credits Issued

24,143 verified carbon credits issued under new Regen Registry watershed methodology. Water Environment Federation purchased 1,000 credits.

Market Recognition

Early Credit Buyers

The Water Environment Federation purchased 1,000 credits and designated the Madison Metropolitan Sewerage District as the official climate partner for WEFTEC 2026—the world’s largest water quality conference.

M.A. Mortenson Companies acquired and retired credits as part of a 2023 pre-sale agreement to address operational emissions, demonstrating corporate demand for high-quality watershed carbon credits.

Phosphorus Reduction Results

Yahara WINS partners have collectively prevented over 258,000 pounds of phosphorus from entering the Yahara Watershed over the past decade. In 2024 alone, 59,124 pounds of phosphorus were kept out of the watershed—protecting the Yahara chain of lakes and downstream water quality.

Technology Evidence Base

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