Guest Opinion — Shadow Cliffs: A microcosm of California’s water complexities

Growing up in Pleasanton in the 1980s, I felt fortunate to have a fun place like Shadow Cliffs in my hometown. Today I am driven by a sense of responsibility to ensure Shadow Cliffs remains a place for all to enjoy and cherish.

Shadow Cliffs Lake is an example of California’s challenges in managing water resources. Our state is affected by long-term droughts and unpredictable weather patterns, making water management difficult.

Climate change has made this even more challenging, as historical models for forecasting are less reliable. As a result, there is a need for innovative and adaptive approaches to water management to ensure adequate water supply for California’s population and economy.

The low water level at Shadow Cliffs Lake has served as a visible reminder of the severity of our recent drought. Californians were surprised to welcome the start of 2023 with a series of atmospheric rivers bringing heavy rains to the Bay Area, an amount of rainfall not seen in a three-week period since the 1860s.

This sudden change in weather caused confusion as to why the water level at Shadow Cliffs Lake did not rise immediately despite the heavy rainfall.

Shadow Cliffs opened as a park in 1971 after Kaiser Industries donated the former gravel quarry to the East Bay Regional Park District. The quarry was turned into a lake, even though water does not naturally flow. The Zone 7 Water Agency manages the availability of water to transfer from the nearby Arroyo Del Valle into Shadow Cliffs Lake.

This agreement is a part of Zone 7’s “Annual Report of the Sustainable Groundwater Management Program for the Livermore Valley Groundwater Basin”. A review of the reports includes a note in the 2017 report describing the agreement as a “cooperative off-site recharge program” with EBRPD, with Shadow Cliffs Lake serving as a “spreading basin.”

The 2021 report stated that Zone 7 could not provide any water for Shadow Cliffs Lake due to the severe drought. I anticipate the 2022 report will include a similar statement.

The Arroyo Del Valle is a part of the Alameda Creek Watershed, one of the largest watersheds in the San Francisco Bay Area. Zone 7 does not have sole decision-making authority regarding the water flowing through the Arroyo Del Valle, as California water laws govern water rights. For example, some water must remain in the arroyo for downstream flow throughout the watershed. As a result, under severe drought conditions, consultation with multiple stakeholders is necessary before stormwater can be approved to transfer into Shadow Cliffs Lake.

I am following Zone 7’s proposed Chain of Lakes pipeline project as a potential solution for future water management. This project could be an innovative and adaptive approach to managing our local water resources. I plan to work with Zone 7 to explore the potential benefits of this pipeline and how it can help to ensure a more stable water supply for Shadow Cliffs Lake.

Today, Shadow Cliffs is popular for outdoor activities such as picnicking, hiking and birdwatching. The park features a new interpretive pavilion with an impressive 3D relief of the Alameda Creek Watershed area.

In fact, this past weekend, I had a great day at Shadow Cliffs! I started with lunch at the nearby BottleTaps Restaurant, walked to the connecting trail and then to Shadow Cliffs, where I continued to explore the area on foot. Shadow Cliffs is a great local option for those who want to experience nature in a beautiful and peaceful setting. I encourage people to visit Shadow Cliffs and enjoy its many recreational activities.

Editor’s note: Olivia Sanwong serves on the East Bay Regional Park District Board of Directors for Ward 5, which includes Shadow Cliffs in Pleasanton. She previously served for 4-1/2 years as an elected director for Zone 7 Water Agency. She said the opinions expressed are solely hers and do not reflect the views of any current or previous affiliations.