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Results at a Glance
- 50% reduction in vegetation-related outages annually
- 260 hours saved per year for the forester
- Less than 8 weeks from start to system-wide active deployment
Challenges
Historically, Hetch Hetchy relied on periodic LiDAR surveys and manual field work for inspections. One forester was responsible for inspecting all 45 miles of distribution line and 324 miles of transmission line at least once a year, using LiDAR for an overhead view, navigating with a handheld device, and performing manual distance calculations with tools like range finders.
This approach created several issues. It was time-consuming and difficult to scale, and manual distance calculations in the field increased the risk of errors. LiDAR flights were also subject to aircraft availability, weather delays, and visibility constraints. In one case, a LiDAR survey took more than 18 months to deliver insights, by which time vegetation conditions had already changed and the data was no longer actionable.
The Solution: From Reactive to Proactive Vegetation Management
Hetch Hetchy wanted to transform its vegetation management and adopt a more proactive, data-driven model. To achieve this, it partnered with LiveEO and implemented Treeline, a satellite-powered and AI-enabled vegetation management platform, chosen for its scalability, cost benefits, and speed advantages over LiDAR.
Treeline gives Hetch Hetchy an up-to-date, system-wide view of vegetation risk, delivering full situational awareness of potential encroachment and fall-in risks to conductors. Its predictive analytics also highlight vegetation likely to grow into the regulated clearance space in the next 1–2 years.
This model enables Hetch Hetchy’s vegetation management team to:
- Prioritize work and focus on the highest-risk spans
- Plan crews and budgets more efficiently
- Support long-term planning to stay ahead of risks and maintain clearance requirements
- Undertake timely interventions, with insights available as early as eight weeks after imagery collection instead of over 18 months with LiDAR
"Using Treeline, I can request the data in spring, get it in the summer, and hit the ground running before there’s a lot of change in the environment.” — Joy Mellera, Right of Way Manager, Hetch Hetchy
The Outcome: Enhanced Grid Reliability and Operational Efficiency
In the three years since deploying Treeline, Hetch Hetchy has seen significant improvements, including a 50% reduction in vegetation-related outages annually and a substantial decline in vegetation maintenance effort. For example, Treeline saves the forester around 260 hours of work annually, freeing up time for other tasks that reduce risk and improve reliability.
Operationally, Treeline has transformed how Hetch Hetchy manages vegetation risk. It allows the team to demonstrate full inspection coverage of the network, visually track the progress of vegetation work over the years, and help stakeholders even without a forestry background understand risk levels and work completed, supporting better decision-making.
"Our management team can use Treeline to understand how the vegetation management program is working and how it’s improving year to year without having to dive into spreadsheets and numbers. They can visually see that there’s less risk on the system and we’re doing what we should do.” — Joy Mellera, Right of Way Manager, Hetch Hetchy
Using Treeline Beyond Routine Vegetation Management
Hetch Hetchy also uses Treeline beyond day-to-day vegetation management. During public safety power shutoffs (PSPS) in remote areas affected by wildfires, the team can use Treeline to pinpoint where vegetation risk is highest instead of conservatively shutting off much longer sections of the line.
Treeline’s insights also inform long-term grid planning. While Hetch Hetchy prefers to prune rather than remove trees, this can mean returning to the same locations every few years. By highlighting areas with persistently high vegetation pressure, Treeline helps identify where it is more effective to move lines underground, reducing future maintenance and improving network resilience.
Next Steps: Expanding AI-Driven Situational Awareness
Looking ahead, Hetch Hetchy is exploring ways to deepen its use of AI and satellite data.
It plans to increase the frequency of its satellite analyses to twice a year and use the data to address hazards along access roads to its facilities. It is also exploring how AI can further reduce risk by incorporating tree species information, such as black oaks that may experience sudden limb failure and fast-growing eucalyptus, so it can better target maintenance and anticipate potential issues.
Together, these steps will build on the results Hetch Hetchy has already achieved with Treeline, further reducing vegetation-related risk and enhancing overall grid reliability.
