When the New Year's storm rumbled through Lodi, the city received about 3 inches of rain in about three days.
Doesn't sound like much, but if one considers an inch of rain falling on one acre equals 27,154 gallons of water, according to the United States Geological Survey, three inches falling over Lodi's 12 square miles equals more than 625 million gallons.
It's a huge amount of water. But just hours after the storm passed, Lodi's streets were clear and the city remained largely flood free.
Other cities, in more flood prone areas such as Napa and Sacramento are still cleaning up the damage.
Lodi benefits from its geography and its system of basins that collect millions of gallons of stormwater through the force of gravity.
Public Works Director Richard Prima said that wasn't always the case.
The city flooded regularly in the 1940s and 1950s and one solution posed early on was a series of large ditches - not unlike the Woodbridge Irrigation District (WID) canal. They would wound through Lodi and collect stormwater and carry it out of the city.
Needless to say the idea wasn't too popular, and Prima said the city instead went toward a "detention basin" system.
The basins now serve double duty as parks and were paid for out of bonds secured in the 1960s.
"Basins basically take water off the streets passively," Prima said. "We don't have to pump into them, they work by themselves."
The system works like this:
As rain falls, the water is collected through catch basins (the drains located in curbs), and then flows into storm drains that carry the water into the larger detention basins in parks.
Once in the basins, the water is pumped into the WID canal or directly into the Mokelumne River. Stormwater in the WID canal is then dumped into Pixley Creek between Lodi and Stockton, but eventually it all reaches the Delta.
Lodi has eight basins, some of which include Beckman Park near Century Boulevard and South Ham Lane and Henry Glaves Jr. Park located near Lodi Avenue and Lower Sacramento Road.
The largest basin is Salas Park, located at South Stockton Street and East Century Boulevard, and has a capacity of 94 acre feet of water. One acre foot of water equals about 325,000 gallons of water. All of Lodi's detention basins can contain 728 acre feet.
One of the obvious benefits to the basins is that they can serve as recreation fields during the dry months and one Vinewood Park even has a dog park.
He said other cities in the Valley, such as Manteca and Fresno, have basins and Prima periodically receives phone calls from officials in other cities inquiring about Lodi's.
Lodi's storm system: By the numbers5 inches, 48 hours: The "century storm," or maximum the city's system is designed to accommodate
8: Number of parks with detention basins, which also serve as large holding ponds for storm water which is eventually pumped into the Mokelumne River or the Woodbridge Irrigation District canal
14 pump stations
18 river outfalls
112 miles of underground storm drains
3,300 catch basins
27,154: Number of gallons in one inch of rain falling on one acre
Sources: City of Lodi, USGS
The basins are vital to keeping Lodi's streets clear of water, but blocked drains or excessive rainfall can cause system overload.
Just like if you open the drain on a full bath tub while the faucet is running and the tub's water level doesn't noticeably change, so too can water back up in Lodi's streets if there's just too much of it.
The city witnessed that situation about two weeks ago when a 45-minute deluge struck and Lodi's sewers were essentially overwhelmed. Intersections throughout the city quickly pooled up with water.
During the recent storm, the system started to back up on some streets, but those puddles cleared as the rain abated.
Older properties built only a few inches above the streetline can see some flooding in such situations.
If the city's drainage system is totally overwhelmed and Lodi does flood because of a storm, Prima said the city also naturally drains.
While the town may seem flat, northeast Lodi is actually at about 55 feet elevation and the southwest corner is around 30 feet.
That 20 feet in elevation change could provide natural drainage for most of the city, he said. Yet, he added, the WID canal's raised banks create a barrier to that flow and could create isolated pockets of flooding.
Prima said the city's system is designed to contain a "century storm" event, or about 5 inches of rain in 48 hours.
The city's wastewater fund budget stands at more than $16.5 million, and to keep the stormwater flowing smoothly, Prima said it undergoes regular maintenance.
He said often times crews have to clear out chunks of plastic, wood and even rug pieces to keep the pumps and storm drains clear.
One time a crew discovered about 25 inches of cement, stucco and other material that had hardened in a 48-inch storm drain.
"It wasn't as hard concrete. We were able to chip it out, but it was a huge problem," Prima said.
Some residents don't seem to understand that storm drains lead directly to the river and the water that flows through them isn't treated, Prima said. Hence the little painted fish signs warning residents that dumping into drains leads to the river.
"Lodi has a pretty good system," he added. "We've put time and money in the system, and I think it's paid off."
Contact reporter Andrew Adams at firstname.lastname@example.org.