Toreson, also known as Ballard Reservoir, is a privately owned earth dam located in Canby, California. Built in 1898, this dam serves primarily for water supply purposes, with a maximum storage capacity of 1140 acre-feet. Situated on Toms Creek, Toreson has a hydraulic height of 50 feet and a dam height of 55 feet, making it a significant structure in the region.

Managed by the California Department of Water Resources (DWR) and Safety of Dams agency, Toreson is regulated, permitted, inspected, and enforced to ensure its safety and compliance with state standards. Despite its age, the dam is in satisfactory condition as of the last assessment in September 2017, with a significant hazard potential due to its size and location. The reservoir covers a surface area of 92 acres and has a drainage area of 17.8 square miles, providing water for irrigation and domestic use in the surrounding area.

With its historical significance and vital role in providing water resources, Toreson stands as a testament to the importance of proper dam management and maintenance. As climate change continues to impact water availability and quality, ensuring the safety and efficiency of structures like Toreson becomes increasingly crucial for sustainable water management in California's evolving landscape.