July 13, 2026 (Napa, CA) — Castello di Amorosa and Water Audit California today announced a collaboration for the study of Nash Creek, a significant tributary of the upper Napa River. Historically, the Napa River watershed has supported thousands of steelhead trout, Chinook and Coho salmon, but their numbers have been greatly diminished in the last century. The first phase of the project, beginning in 2026, will include the integration of monitoring equipment to collect data and video of creek conditions and to track water use through the agricultural, winery and hospitality process. The information gathered will guide future habitat restoration and water utilization.
Nash Creek is in the Diamond Mountain District AVA of northwest Napa Valley, flowing down the southeastern slopes of Diamond Mountain in Calistoga. The creek traverses the Castello di Amorosa property for almost a mile, providing an important riparian corridor and habitat for native wildlife. The recharge from rainfall on the undeveloped portion of the property contributes to a balanced sustainable water supply for winery operations. “Our responsibility extends beyond growing grapes,” said Georg Salzner, President. “We are caretakers of this land; we have an opportunity to help restore an important piece of Napa Valley’s natural ecosystem and we’re proud to partner with Water Audit California on this effort.”
Castello di Amorosa is an iconic winery in Napa Valley, California, a medieval-style castle passionately designed by owner Dario Sattui. The 170-acre estate reflects Castello di Amorosa’s long-standing commitment to environmental stewardship. The property features organically farmed vineyards surrounded by native forest, more than 100 fruit trees, an apiary, a solar energy system, and an extensive reclaimed water program designed to conserve natural resources while protecting the surrounding ecosystem. Dario holds a strong belief that protecting the environment and responsible stewardship will allow future generations to enjoy the beauty of Napa Valley.
Water Audit California is a Napa-based NGO that advocates for the public trust in watercourses and fish. Guided by a distinguished panel of advisors with a mission statement “we manage what we measure,” Water Audit is focused on remediating fish habitat using contemporary techniques with the objective of restoring populations to historical levels. For this project Water Audit has assembled a multi-disciplinary team well known in Napa, including Dr. Robert Leidy (environmental professor emeritus UC Berkeley and co-author of the seminal book on Napa fisheries) and Dr. Ted Grantham (hydrology professor UC Berkeley), and field biologist Chad Edwards (NOAA, Napa RCD).
By combining scientific monitoring with long-term stewardship, the data acquired by this project will model the transparency and balance necessary to reconcile successful agricultural and hospitality operations with healthy watercourses in the Napa Valley.
