Sacramento-San Joaquin River Delta, United States

Location: Sacramento-San Joaquin River Delta, California US

Impact: Environment and agriculture

Focus: Species conservation and pollution

Technician installs camera-like HydraSpectra sensor on metal beam with water in the background.

AquaWatch is being tested in the Sacramento-San Joaquin River Delta in the US, to monitor water quality and improve ecosystem management.

The pilot site, located in California where the Sacramento and San Joaquin Rivers merge, uses specialised water quality sensors to monitor water delivered for agriculture and to protect the delta’s natural ecosystems.


Protecting freshwater wildlife

Endemic to the Sacramento–San Joaquin River Delta is the delta smelt, a small, critically endangered fish species that relies on the delta’s freshwater and brackish environments for its survival.

Due to its one-year lifespan and limited reproductive capacity, it is highly vulnerable to changes in the environmental conditions of its natural habitat. With declining populations, the delta smelt faces numerous threats including habitat loss, pollution, and changes in water quality.

Monitoring the water quality of the Sacramento–San Joaquin River Delta, particularly its turbidity, is crucial for the smelt’s protection. AquaWatch provides valuable data for monitoring water conditions and tracking the movement of harmful contaminants like mercury, helping decision-makers protect the delta smelt and its ecosystem.


Implications for water management

The use of AquaWatch in the Sacramento-San Joaquin River Delta helps detect water quality issues by monitoring turbidity levels and identifying and tracking potential contaminants, enabling water managers to take proactive measures to protect both the ecosystem and water supply for agriculture.


Partners and collaborators

University of California, Davis

University of California, Merced

USGS Water Science Laboratory