It is coming.
On Monday afternoon, Turlock Irrigation District officials opened the controlled spillway at Don Pedro Reservoir to nearly double the flow down the Tuolumne River in anticipation of high reservoir inflows from a warm storm currently battering Northern California.
It’s the first time since 1997 that the decision has been made to open the open the emergency valves.
That means that by today sometime between 11 a.m. and 3 p.m., the torrent of water that has been released – and is expected to be released continuously for the next four days – will have made it through the San Joaquin River, raising it above the 30-foot threshold at Vernalis and putting additional stress on the levees that protect hundreds of thousands of acres of farmland, as well as thousands of homes, in South San Joaquin County.
On Saturday, the San Joaquin River at Vernalis was declared to have reached danger stage as water began to inch up towards the tops of the levees that contain it – the first time in this cycle of high water that the “threat to life and property in the event of levee failure” had been formally declared.
According to San Joaquin Office of Emergency Services Spokesman Tim Daly, the releases from Don Pedro are expected to raise the level of the river even higher once the water makes its way through Tuolumne County, parts of rural Stanislaus County and ultimately the City of Modesto before it ends up winding back into farmland and dumping into the San Joaquin River.
All of that water being released will flow into the San Joaquin River between Patterson and Vernalis before making its way into South San Joaquin County and past many of the levees that broke during the floods of 1997.
According to the National Weather Service’s forecasting map, the river will continue to rise at Vernalis through the end of the week and will approach 32 feet – the next level of concern for planners and engineers who are trying to manage a record amount of water.
“We’re encouraging people who live in areas that have historically been affected floodwaters to be prepared at this point,” Daly said. “But that doesn’t mean that people who don’t live in areas that haven’t been subjected to floods in the past should ignore what’s going on. We’re also encouraging people who think that their homes may be safe or out of the way to be aware of what is happening and consider their own plans in the event something unexpected happens.”
Last week farmers in South Manteca and rural San Joaquin County began the process of readying themselves for any possibility – moving heavy equipment to higher ground, hauling out livestock, and building makeshift berms around properties to protect animals and equipment that cannot be moved in time.
Volunteer crews of landowners and contracted engineers have been patrolling the levees heavily since early last week – marking trouble spots like boils and checking back on their progress – and will continue to do so as the waters continue to rise higher than they have in more than a decade.
While California has been suffering through its worst drought in history over the past five years, nearly a full year’s worth of rain in the first month of 2017 has saturated the ground to the point that water that was desperately needed to refill a depleted aquifer has nowhere to go. And it hasn’t done much to help prevent the seepage from the high river in areas that border the levees – flooding entire fields in South Manteca and overwhelming pumps designed to filter the water back into the adjacent river.
Since 1997, many communities in the South County have developed residential tracts in areas that were either affected by floodwaters, or were impacted by them – including Lathrop, which has built hundreds of homes in the River Islands development on top of Stewart Tract. That land, according to water experts, served as a release valve for the river to take pressure off of other more populous areas. Now that entire area is protected by 300-foot wide levees that eliminates that fallback plan.
And while the berm of I-5 served as a last line of defense for residents of Lathrop east of the interstate, hundreds of homes have since been built in the land between the freeway and the river.
According to Lathrop Mayor Sonny Dhaliwal, city staff and emergency crews have been paying close attention to what’s happening along the river, and will do everything possible to protect the lives and the property of those who call Lathrop and the surrounding area home. 
“We are keeping an eye on the flood level and a team of people – Reclamation District 17, the Lathrop Manteca Fire District, Lathrop Police, the San Joaquin County Sherriff’s Department, our own city staff – are all working together on this,” Dhaliwal said. “We are fighting nature and mankind is no match against nature. I would like all of our residents to be on guard and prepare themselves for any eventuality.
“Let’s hope for the best but prepare for the worst.”
While no mandatory evacuation orders have been given for residents elsewhere in San Joaquin County, several communities like the San Joaquin River Club between Manteca and Tracy and the Two Rivers RV Park have been notified that they could be evacuated at any time.
Entire neighborhoods along the Tuolumne River have had their power cut off in anticipation of flood waters, and according to emergency planners involved with managing the situation, a similar approach has been taken with some low-lying pockets of the county to prevent live power lines from energizing the water and threatening the safety of other residents or emergency and work crews that might be operating in the area.
Those who feel they may be affected by the rising water are encouraged to:
uGas up their vehicles so that in the event they’re evacuated so they can get far enough away from the scene of the incident.
uHave some cash on hand to purchase goods or services in areas that may be affected by power outages.
uHave roughly a week worth of food for yourself or your family in the event that local supermarkets or food stores are cleaned out after an evacuation order.
uHave medications and necessary documents handy so that they can be taken if an emergency orders comes down.
uHave a place where they can go if they get the call to leave their home and their belongings behind.
According to Daly, emergency shelters through organizations like the Red Cross are being planned in San Joaquin County and the location will be disseminated in the event that any evacuation orders are issued.
Initial flood warnings will be sent out on KFBK 1530 AM and 93.1 FM on behalf of San Joaquin County, and emergency radio frequencies will also be used. Those who feel they may be forced to shelter in a building due to floodwaters are urged to make sure in advance that they have access to the roof of the building, and to have either a flashlight or a bright cloth on hand to signal rescuers.

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