Why was the Don Pedro Project built?

In the 1920s, the Turlock Irrigation District (TID) along with the Modesto Irrigation District built the first Don Pedro Dam. With a small storage capacity of 289,000 acre-feet (AF), the dam held only enough water to accommodate growers’ irrigation needs for a single growing season.

After numerous dry winters, the Districts made the decision to replace the original dam with a much larger one in order to store water necessary to bridge multiple years of drought. The New Don Pedro Project was completed in 1971 and has storage capacity of 2,030,000 acre-feet, seven times larger than the original. The Don Pedro Project and our 250 miles of gravity-fed canals serve irrigation water to nearly 150,000 acres within the TID service territory.

What are the benefits of the Don Pedro Project?

The Don Pedro Project stores and delivers irrigation water to some of the most productive farmland in the world. With affordable, reliable irrigation water, the Project directly supports the vibrant agricultural sector that has evolved since the Districts’ formation. The Don Pedro Project also provides municipal and industrial water supply, flood control storage, recreation, power, and fish and wildlife conservation benefits.

According to the Socioeconomic Study Report completed in April 2014, the Don Pedro Project supports approximately $4.109 billion in output, $734.8 million in labor income and 18,900 jobs annually. These numbers reflect the positive direct and indirect economic effects on the entire regional economy within Stanislaus, Merced and Tuolumne counties.

Why do we need a license?

The Federal Energy Regulatory Commission (FERC) has the authority to license dams with power plants on navigable rivers. Since the Don Pedro Project has a 203-megawatt (MW) powerhouse at the site, it falls under the jurisdiction of FERC.

What authority does FERC have?

FERC has the authority to license and relicense non-federal hydropower project for terms between 30-50 years. FERC is mandated to give equal consideration to beneficial public uses (including energy conservation, irrigation, flood control, water supply, recreational opportunities, and other aspects of environmental quality) and adequate protection, mitigation and enhancement of fish and wildlife.

When did the Districts’ license expire?

FERC issued the Districts a license for the Don Pedro Project in 1966, and that license expired on April 30, 2016. Since 2011, the Districts have been working towards acquiring a new license utilizing FERC’s Integrated License Process (ILP). Following extensive consultation with resource agencies, tribes, and multiple conservation groups, as well as the FERC, the Districts filed an amended final license application on October 11, 2017, referred to as the Tuolumne River Management Plan.

What is the FERC Integrated Licensing Process (ILP)?

The ILP is intended to streamline FERC’s licensing process by providing a predictable, efficient, and timely licensing process that continues to ensure adequate resource protections. If data gaps exist in the FERC record, the ILP creates a collaborative process among stakeholders to identify how to best fill the data gaps prior to a license application being filed.

The Districts intentionally selected the FERC ILP desiring to work alongside the state and federal agencies and other interested parties and stakeholders – at the beginning of the process – toward an agreed-upon set of license conditions that balance the water supply, hydroelectric, flood control, recreational and environmental uses associated with the Don Pedro Project.

What does FERC consider during the licensing process?

The licensing process looks at both the benefits of hydroelectric power generation and the environmental impacts associated with all aspects of the project, not just the dam, including operation and maintenance. Since the project was licensed more than 50 years ago, resource agencies and other interests have offered their input on both the Don Pedro Project and the Tuolumne River watershed.

Where can I learn more about the licensing process?

The Federal Energy Regulatory Commission offers more details about the entire hydroelectric licensing process on the FERC website. You can also see a list of documents related to the license under the Documents section of this website.

Why did the Districts invest in site-specific science?

While the Tuolumne is among the nation’s most studied rivers, the Districts identified during FERC’s Integrated Licensing Process (ILP) that the existing suite of scientific knowledge on the Tuolumne was, in general, largely outdated, lacking a collaborative approach, or was informed by data more relevant to other projects or rivers that do not share the unique characteristics of the Don Pedro Project or the Tuolumne River.

The existence of these scientific data gaps became evident as the Districts embarked upon the ILP process. In order to best evaluate new operating conditions for the Don Pedro Project, these data gaps needed to be addressed with updated, focused, site-specific science designed within the inclusive ILP process. The Districts invested in 35 such studies at a cost of $20 million. The results from these studies formed the foundation of the Districts’ license application submitted to FERC.

What studies were conducted and who did them?

The Districts funded more than 35 studies, conducted by well-regarded consultants, scientists and academics, that examined, among other items, the Don Pedro Project’s potential effects on historic properties, Native American cultural sites, public recreation, federally protected species, state protected species, water quality, water temperature, instream flow, resident and anadromous fish populations both in the reservoir and downstream of the project, terrestrial species and regional socioeconomic resources.

What is the Tuolumne River Management Plan?

The Tuolumne River Management Plan was created by the Districts for the proposed operations, improvements, and resource protection measures under a new FERC license for the Don Pedro Project. The plan achieves the co-equal goals of protecting and improving the natural resources of the lower Tuolumne River and protecting and sustaining the water supplies to our community.