In the Sacramento Valley, the Delta Breeze is called “nature’s air conditioning.” But as Metropolitan’s Executive Strategist
wrote in last week’s Water Deeply publication, “the blessed Delta breeze isn’t what it used to be.”
This lack of wind has actually shifted the ecology of the Sacramento-San Joaquin Delta. That's important to the reliability of Southern California’s water supply since about one-third of our region’s water comes through the Delta in an average year.
Earlier this year,
, a researcher for Metropolitan, co-authored a study that was published in the scientific journal,
Estuaries and Coasts
, which looked at wind in the Delta and found declines ranging from 13-48% throughout the estuary. The research applied sophisticated modeling tools to estimate how the Delta is changing as a result of the decreased winds.
Wind is a primary driver of turbidity (cloudiness) in Delta waters. Take the Suisun Bay as an example. There, winds can suspend sediment in shallow channels. Then, the extraordinary power of the tides help distribute this turbid water to deeper channels throughout the Delta.
Why does that matter? Turbidity is a documented factor in the survival of the endangered Delta smelt fish -- which seem to like turbid water to hide as they migrate.
Less wind means less turbidity, which means less cover for a fish such as the Delta smelt. This species is under stress for many reasons. Now add wind, or the lack of it, to the list.