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Crews loaded the 130,000 pound stainless steel cone onto a barge and finished assembling it above water before lowering it into the reservoir. Image: Water Authority

New Oxygenation System to Improve Reservoir Water Quality

The City of San Diego’s Public Utilities Department last week took a major step toward completing an innovative project to improve water quality in Lake Hodges. A newly installed oxygenation system, designed by city engineers, will introduce highly oxygenated water to the bottom of the reservoir to reduce the accumulation of excess nutrients and harmful algae growth.

The increase of nutrients and algae in the water has been caused by human activities in the watershed upstream of the reservoir, including residential and commercial development, agriculture, and land clearing. Degraded water quality can restrict the ability to move water in and out of the reservoir.

“The ‘Speece cone’ is a fairly unique method for adding oxygen to a reservoir – there are only a few of them in the world,” said Jeff Pasek, project manager at the City of San Diego Public Utilities Department. “This project derived from a planning study that was done about five years ago, which identified oxygenation using the ‘Speece cone’ as being the most cost-effective way of addressing the water quality problems in Hodges.”

Last week, the 130,000 pound cone – named after the inventor of the technology, Richard Speece – was lowered eighty feet to the bottom of the reservoir.

Streamlined operation for maximum efficiency

The precisely coordinated operation involved lifting the 20-foot tall stainless steel cone with a large crane, while simultaneously driving a barge out from underneath. Once the cone was lowered into the water, divers headed to the bottom of the reservoir to unhook the cone from the crane, check to make sure it settled in the correct spot, and fasten it down.

In order to build a solid foundation underwater, crews excavated approximately 11 feet of silt from the bottom of the reservoir and constructed a concrete base. Before submerging the cone, crews installed and tested a pump that will move water through the cone. A large diffuser pipe was then lowered and connected to the cone by divers. The diffuser will distribute the oxygen-rich water throughout the reservoir.

Now underwater, the cone will distribute oxygen-rich water throughout the reservoir to reduce the accumulation of excess nutrients and prevent harmful algae growth. Image: Water Authority

Now underwater, the cone will distribute oxygen-rich water throughout the reservoir to reduce the accumulation of excess nutrients and prevent harmful algae growth. Photo: Water Authority

Local and regional benefits at Hodges Reservoir

Hodges Reservoir is owned and operated by the City of San Diego, and it serves the San Dieguito Water District and the Santa Fe Irrigation District. It is connected to the San Diego County Water Authority’s Olivenhain Reservoir as part of the Emergency & Carryover Storage Project, which is designed to ensure regional water reliability in case of emergencies or if the region is cut off from imported water supplies.

“There are multiple benefits to this project – first and foremost being the water quality improvements for Hodges Reservoir,” said Goldamer Herbon, a senior water resources specialist at the Water Authority. “Ancillary benefits include operational flexibility for regional supply benefits and preventing the accumulation of mercury, which can be harmful to people and wildlife that eat fish from the reservoir.”

The California State Department of Water Resources awarded the City of San Diego a $3.4 million grant funded by the San Diego Integrated Regional Water Management program to complete the oxygenation project, which began in February 2019.

Two More Rounds of Rain, Mountain Snow Ahead For California Into This Weekend

California will receive two more rounds of rain and mountain snow through this weekend, continuing a stormy period that kicked off before Thanksgiving.

For now, drier conditions have developed and generally will be in place for most of Tuesday.

A low pressure system brought over 2 inches of rain to parts of the Central Valley north of Fresno. Some foothills and mountain locations below snow level in the Sierra Nevada, Santa Cruz Mountains into Napa and Sonoma counties measured over 4 inches of rain.

San Diego Got More Rain Than Seattle in November

Normally sunny San Diego got more rain than Seattle last month, a reverse of what residents of both West Coast cities have to come to expect.

The National Weather Service recorded just under 3 inches of rain with their monitoring station at Lindbergh Field this November, making it the wettest November on record for San Diego.

Trading Water: Can Water Shares Help Save California’s Aquifers?

California is by far the United States’ most populous state, as well as its largest agricultural producer. Increasingly, it is also one of the country’s most parched places.

But Edgar Terry, a fourth-generation farmer in Ventura County, just outside Los Angeles, thinks he has a key to reversing worsening water stress: establishing tradeable rights to shares of fast-depleting groundwater aquifers.

Doing so would turn aquifer water into a more valuable asset that could be traded on a market, similar to “cap-and-trade” systems that have been set up to regulate air pollution, conserve fisheries and manage other such common resources.

Water In The Bank: Coalition Of Agencies Develops ‘Historic’ Sustainable Groundwater Plan

There’s progress to report in the momentous task of ensuring that San Joaquin County and surrounding communities have enough water to meet anticipated needs for the next 20 years.

Earlier this month, the Eastern San Joaquin Groundwater Authority — or ESJGWA, comprised of 16 area agencies including cities, counties and water districts — recommended that each of its member agencies adopt a mutually agreed upon Groundwater Sustainability Plan by Jan. 8.


Conservation Groups Sue Feds Over California Water Projects Opinion

Several fishing and conservation organizations brought a federal complaint Monday over the harm they expect to befall an already threatened species of fish from the Trump administration’s efforts to set new rules for the operation of major California water projects.

Led by the Pacific Coast Federation of Fishermen’s Associations, the groups claim that the government’s biological assessments of the Central Valley Project and State Water Project were politically motivated and failed to consider proper environmental protection standards. They filed their suit in U.S. District Court for the Northern District of California.

How The Atmospheric River Storm Affected Bay Area Rain Totals

Remember fire season and power outages? They seem so long ago now.

The cold storms that suddenly doused the Bay Area over the past week instantly flipped a switch from summer to winter weather conditions. But so far, they have brought radically different amounts of rain to communities across Northern California.

“We basically went from fire season to rain season in a matter of 48 hours,” said Matt Mehle, a meteorologist with the National Weather Service in Monterey. “We’re making progress, but we could still use some more rain.”

Water Quality Reported Safe In Ramona

Although city of Poway residents and businesses are being impacted by water quality issues, the Ramona Municipal Water District (RMWD) reports there are no potable water quality issues in Ramona.

Despite swirling rumors, RMWD General Manager David Barnum said Poway’s water issues are not impacting Ramona’s water supply.

“The treated water system is safe, no water boil alerts are required and restaurants are not impacted in Ramona,” Barnum said on Monday, Dec. 2.

Backed-Up Storm Drain Caused Poway’s Water Contamination

Poway officials said Monday they believe backed-up storm drains caused the water contamination that led to the city’s first-ever boil water advisory over the weekend.

The county health department ordered the closing of all restaurants in the city and residents are being advised to boil their tap water before drinking it or using it for cooking, city officials said.

The recent rains caused the storm drains to back up into its water treatment facility, officials said. They added that crews are working around the clock to clean and flush the system, which may take two to five days before the water is declared safe.

Storm Runoff Blames For Railroad Track Washouts On Fragile Del Mar Bluff

A second spot may need repairs after an unusually wet Thanksgiving Day storm closed the railroad tracks at Del Mar for work over the weekend, transit district officials said Monday.

The “area of concern” is less than a block away from the spot fixed Saturday, North County Transit District Executive Director Matt Tucker said Monday in an email to the district’s board of directors.

The additional job needs an engineering design plan before the work is done, and it may wait until January to be included in the next phase of the district’s ongoing bluff stabilization work, Tucker said.