One night, my husband came home with an announcement: he’d adopted a drain.

I paused before reacting.

Well, this is something, I thought.

Large businesses and wealthy people adopt schools. Suburban dwellers adopt trees. If we lived in a house in the East Bay, my husband might come home one night and tell me he’d adopted a pet.

But we live in multifamily housing in San Francisco. Under these circumstances, a drain is probably the best we can do.

While I was contemplating an alternate existence in which I tended an organic garden behind my Craftsman bungalow in Oakland, my husband was excited about his new drain.

He told me about contacting the San Francisco Public Utilities Commission, which has run an Adopt-a-Drain program since 2016, and selecting the large drain at the corner of our street. Our street is slightly elevated, but the pockmarked blacktop is prone to sinkholes, and he thought that keeping the drain clear would prevent frighteningly large pools of water during hydrant blowouts and heavy rains.

I nodded and smiled. (I was still dreaming about backyard space, CDC-approved homegrown lettuce and dogs.)

The days passed. I supported my husband’s adoption endeavor. He’d march outside with a rake and the determination to clear our street drain of the cigarette butts, fast-food wrappers and foliage it collected on a daily basis. I’d wave from the kitchen window. “How nice,” I’d think each time.

Still, I never considered the drain cleaning to be a pressing, necessary enterprise: Everyone knows it never rains in California anymore.

Then came this week.

The rain poured on Tuesday, sprinkled on Wednesday morning, and thundered down Wednesday night. On Thursday morning, my husband left the house early for work. I strolled around our neighborhood to have a look at things. Though it was strewn with the usual urban trash and some fallen branches, there was no standing water on our street. The large, cleared drain on the corner gurgled happily when I walked by.

Two blocks down, the streets are lower and the residents weren’t so lucky. Pools of water had gathered by each curb, endangering pedestrians with a filthy splash every time a car drove by.

The corner store merchants had heaped sandbags to prevent the high water from running into their stores. I looked at the drains. They were clogged to bursting.

“No matter how much we plan for rain, we’re an urban system and we’re going to have to deal with flooding,” said Will Reisman, a spokesman for San Francisco’s Public Utilities Commission.

I called Reisman to find out how well the program was working. He told me that when the PUC launched the Adopt-a-Drain program, it faced criticism. Some people think it’s unseemly for a city government as large and well-funded as San Francisco’s to depend on volunteer initiative for a service as important as street maintenance.

But the PUC launched the program anyway.

“We’ve proposed $700 million of flooding prevention work in our sewer improvement program, which will be rolled out over the next 15 years,” Reisman said. “But until then, there are 25,000 drains in this city and the infrastructure is more than 100 years old. So we need a little extra help.”

So far, 1,600 people have adopted 2,500 drains, said Reisman. The volunteers run the gamut — they’re young and old, all genders and ethnicities. The commission calls them “drain heroes.”

This week, the commission launched a digital map showing the qualities of every drain in the city: which ones run to the ocean, which run to the sewer and which ones are still in need of adoption. It’s a great resource if you’re looking to save your own street from flooding.

This is particularly true for people who live in the lowest-lying areas of the city. Those areas are all over the map. The 15th Avenue area near Wawona Street in West Portal is a hot spot, and so is 17th and Folsom streets in the Mission. In Ingleside Terraces, the Ocean Avenue area near Urbano and Victoria is in need of help. Stormwater naturally accumulates in much of the Sunnyside Terrace neighborhood, because the bottom of the hills there were creek channels.

Adopting a drain doesn’t get you much in the way of public recognition. It’s certainly not as obvious as a new tree, a shiny new school or a new puppy (which, let’s face it, would tear up the organic vegetable garden of my dreams anyway).

But this week, my husband and I were pretty happy knowing that he’d kept trash out of the ocean — and kept our street from turning into a Slip ’N Slide.

Caille Millner is a San Francisco Chronicle staff writer. Email: cmillner@sfchronicle.com Twitter: @caillemillner