For Lake Los Carneros to remain relatively healthy (little or no eutrophication) it needs about 16-18 inches of rain for at least two years in a row (Goleta Fire Station rainfall monitor). According to the monitor from rain year 1941-1942 through 1955-1956 this was not the case. But in 1955-1956 the trend started to change. Except for a few years in the late 50s/early 60s and early 70s the rainfall totals were close to average for at least two years in a row. In fact, for a 10 year period from 1972-1973 through 1982-1983 there was never more than a year in a row of below average rain. This coincides with the stories I hear of the lake being "healthy" and full most of the time during the 70s. In the 80's we entered another period where we did not get two years in a row of enough rain and the lake suffered. This pattern ended in 1991 and while it took a couple of years for the lake to spill from 1993 through 2011 there were only five years of less than 17 inches of rain. The lake never dropped below ~9 ft below spill level and was, except for a few years scattered throughout relatively healthy. Similar to the 60s and 70s the lake went through a period of being "healthy and full" most of the time. Unfortunately this 18 year healthy streak ended in 2012 with the start of another period of not getting two years in a row of enough rain.

When I first visited Lake Los Carneros in the Fall 1983 the water level of the lake was ~12 ft. below spill level. A nearly 50 inch rain rain year in 1982-1983 lead me to find out that these low levels were the result of the lake being artificially lowered.

~3 ft. below spill level	~9 ft. below spill level
~11 ft. below spill level	~14 ft. below spill level

This period of low rain caused the water level of the lake to drop to over 15 ft. below spill level in early 1991. The "March Miracle" rain of 1991 produced over 12" of rain in one month brought the lake back up a couple of feet from spilling. Although close to spilling in 1992 the lake did not actually spill (for the first time since 1983) until 1993. The "March Miracle" rain of 1991 was the beginning of another period of 17 inches of rain for two (or more) years in a row which lasted until 2011. During this period the lake spilled numerous times and flourished from the repeated "water changes" nature was providing.

Low Water Level Markers:

~8 ft. below spill level: The bottom of the ladder furthest to the East exposed	~10 ft. below spill level: The ledge just barely exposed
~12 ft. below spill level: The drain exposed and pipe out beyond the drain visible	~14 ft. below spill level: The pipe out beyond the drain exposed

Unfortunately 2012 was the start of another period low rainfall. Causing the water level of the lake to pass 10 ft. below spill level for the first time in over 20 years. In October of 2014 the water level dropped to over 11 ft. below spill level and exposed the drain of the dam for the first time since the "March Miracle" rains in 1991.

April 1993: Lake spills for the first time in over a decade	November 2014: Spillway completely dry
January 2005: Lake spilled causing the water to nearly reach the walking trail through Spooky Cove	October 2015: Nearly a straight line from Frog Beach to Stow Point as the water level reaches ~13.5 ft. below spill level

A little over 7 inches of rain in November and December of 2014 provided an additional 3 ft. of fresh water pushing it back up to just a little over 8 ft. below spill level. This combined with another 4.5 inches of rain in 2015 was not enough to keep the water from dropping to a historic ~13 ft. below spill level by the Fall of 2015.

Spring 2011: Bird's eye view of a completely full Lake Los Carneros	September 2014: Tree Stumps visible as water level reaches ~11.5 ft. below spill level
March 1993: Lake spills for the first time since 1983	April 2001: Lake Full

The water level dropped to over 14 ft. below spill level by December of 2016. Above average rain in February and March of 2017 added nearly 13 feet of water into the lake. Bringing the water level to within a little over a foot from spilling but unfortunately 2018 was another year of below average rainfall. This pattern continued through 2022.

On March 22, 2023 Lake Los Carneros spilled for the first time since 2011. Another 20+ inches of rain in 2024 caused it to spill again in 2024. Prior to that between 1993 and 2011 there were only four years the lake did not spill (or come within a foot or two of spilling).

October 2014: Water level ~12 ft. below spill level	December 2019: Water level ~6 ft. below spill level
July 2014: Tree Stumps just barely visible as water level reaches ~10 ft. below spill level	February 2015: Measuring the water level between storms

Lake Depths

1999 Depth: ~20 ft. (measured using an electronic depth finder)
2011 Depth: ~19 ft. (measured using a marked rope with a weight on the end)

Rainfall & Water Levels

Update - March 24, 2024: Another 20 inch rain year so far. Two years in a row of above average rain. Something that hasn't happened since 2011 and hopefully the beginning of another "wet" period like 1993 through 2011 and in the 70's where the lake never dropped more than 9 ft. below spill level.

Update - March 22, 2023: At just over 28 inches of rain for the 2022-2023 rain year Lake Los Carneros spilled for the first time since 2011.

*Known occurrences of lake being lowered. 2023 was slightly (maybe a foot?). 1982 was all the way to the drain (12 ft. down) just after a historic nearly 50 inch rain year where the lake would have been spilling and then some.

Contact: pete@lakeloscarneros.com