If anybody wants to know how serious the threat of flood is from the levees of the San Joaquin River is to those who live and work near it, they only need to look as far as South Manteca.
Boils that can be the precursor to levees failing are popping up and being plugged as soon as they are found along the 11 miles of levees that are the first line of defense for an estimated 35,000 people in Lathrop, southwest Manteca, Weston Ranch and rural areas.
According to residents that live in the ag-heavy area south of the Highway 120 Bypass – which has become Manteca’s fastest growing area since widespread flooding impacted the area 20 years ago this year – the consensus is to pack up animals and equipment and move it to higher ground as quickly as possible.
This week a steady stream of livestock and flatbed trailers have been seen traveling north on Airport Way – away from the area that was inundated with water when conditions like what forecasters are seeing now aligned to create the perfect storm of opportunity for Mother Nature.
According to Tony Coit, whose family compound was battered by the waters two decades ago, residents with large animals like horses and heifers are moving them out of the area as quickly as possible while dairymen build their own respective levees around their properties to prevent the need to relocate.
And all eyes, at this moment, are on what happens at Don Pedro Reservoir this weekend. With a storm expected to roll in today that will start with a relatively low snow level that will rise to above 8,000 feet by Saturday, everybody from residents and farmers to water managers and elected officials are watching the level at the second largest reservoir in the Central Sierra that is nearly at capacity and is expected to rise with melt from a record snowpack and extensive rain.
The issue rests in the current condition of the Tuolumne River at the 9th Street Bridge in Downtown Modesto which is nearly at flood stage. According to the California Department of Water Resources, flood stage for that stretch of the river is 55 feet and the river is currently at 54.3 feet.
With the outflow from the dam increased from just over 10,800 cubic feet per second on Tuesday to 11,450 cubic feet per second on Wednesday – and a slight decline in the inflow – water managers will be able to make at least some room for the additional water that is expected to come because of this storm.
Per Lathrop City Manager Steve Salvatore, who said the city is talking with representatives from the Army Corps of Engineers as well as the California Department of Water Resources to gauge the status of the reservoir, operators at Don Pedro have no plans to open the floodgates to the reservoir – which haven’t been activated since 1997 when a massive release of water flooded parts of Modesto and contributed to the situation that led to multiple levee failures in the South Manteca/Northeast Tracy area.
Any additional large releases of water would assuredly lead to flooding in Modesto, and would ultimately empty into the San Joaquin River above Durham Ferry which would only raise the levels of water in that area – which is already against the levees – even higher.
Levee watch crews from Reclamation District 17 have been out traversing the river looking for boils or surefire signs that a levee failure could be imminent. The San Joaquin River itself is at flood monitoring stage right now at the Mossdale Bridge, and the height of the water has already flooded out the Haven Acres Mobile Home Park and Resort/Marina. That particular community is located on the river side of the levee, and has no protection from rising waters – a similar situation faced by residents of the homes behind Airport Court, and the mobile homes at the Two Rivers RV Park that were pulled out in anticipation of flooding. All of those places have taken on an abundance of water.
The level of water in Don Pedro has declined in the last 36 hours, and as of press time was listed at 98 percent of capacity – a signal that the additional release of water has worked to create some room for the water that will flow in during the storm.
But what has emergency planners worried isn’t necessarily the immediate impact of this storm, but what will happen in 10 days from now when the water that is released has had time to work its way through completely through the system.
The fact that a record snowpack is currently sitting above the reservoir – enough to fill the lake up more than twice – only worries those who are facing the challenges of preparing for the worst even more.
And as families make the hard decision to pull their farming equipment and their animals out and transport them to other locations, some residents are growing tired of people who just want to come out to “look” to see how high the river is.
“If people really do want to help, then they should stop coming out just to get a glimpse of the river. The lookie loos only end up getting in the way,” said Coit – who took a picture of Hays Road farmer Brian Mazuno pointing out a bubbling boil near his property.
The decision by dam operators at New Melones Reservoir to essentially hold back all of the water that’s flowing in to not stress the downstream system has increased the capacity of the dam by more than six percent in just over 24 hours. That reservoir, which feeds that Stanislaus River, is now at 94 percent of its historical average, and is sitting at 56 percent of its total capacity.

To contact reporter Jason Campbell email jcampbell@mantecabulletin.com or call 209.249.3544.