Another rainy weekend has passed. At least for you, dear reader. At the time of writing, I am unfortunately stuck in the shoe-sogging wetland that is Los Angeles after a light downpour. It seems as though L.A.’s infrastructure is entirely reliant on evaporation — Angelenos give great purchase to the curative powers of their ever-present sun. 

And, like clockwork, your friends from the East Coast will make a point to remind you that this doesn’t happen over there. That their infrastructure can handle similar levels of rain with ease. That L.A. sucks and is designed poorly. The reality is they’re only kind of correct. Unlike its stormwater, L.A.’s drainage problems go far beyond the surface.

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Long ago, when L.A. was a pristine wilderness coexisting harmoniously with its indigenous inhabitants, flooding was a natural part of the annual climatic cycle. The L.A. River, a majestic waterway, would overflow with rainwater during the winter months. As the water flowed, it would slowly seep into the dry Earth, replenishing stores of groundwater and nourishing the environment. The rest would drain into the ocean or evaporate.

Settlers arriving en masse at the turn of the century encountered this phenomenon and felt it was a great idea to build as close as possible to this raging force of nature. To their great surprise, their homes were inundated and their livelihoods were destroyed by the flooding river. 

These settlers, being stubborn or foolhardy, felt the best course of action was to continue building by the river. So the city stepped in and turned the L.A. River, nature’s solution to the L.A. rains, into a concrete channel. 

Nowadays, that surface water gets channeled into the sewer system where it moves sewage and is unceremoniously dumped into the ocean. Of course, not being allowed to drain into the soil as it once did, this water also pools in flat areas until the janitorial sun comes around to mop it up.

But what your East Coast friends may not know is their own rivers have been artificially altered to divert drainage. For instance, as the city of Boston began running out of room for further development around 1900, streams supplying the river were culverted — in other words, covered up — so humanity could expand over them. 

The difference between culverting and channelization is that, in culverts, these feeders into the watershed are still preserved; as long as stormwater flows into these covered streams, water can reenter the natural environment. It’s just not as accessible to the surface. Channels prevent this water recycling, parching the land.

Then why did L.A. not use culverts? One answer: geology. The L.A. Basin is built upon dry sandstone, whereas the East Coast is founded on somewhat rockier, more moist sediment. Crucially, dry sediment has an overall lower capability of liquid absorption, meaning on drier soil, water will have to travel further before being absorbed. In soil with a balanced moisture content, water will be absorbed much better. 

The fact that L.A.’s rain comes in bursts only exacerbates the problem; large amounts of rainfall for short durations are even harder to absorb.

That is why water must travel along the surface — causing floods — in L.A., while on the East Coast, it drains more easily into rivers. Water is not absorbed quickly enough by the soil to prevent percolation. The East Coast handles rain better because it rains more, in short. In addition, 61% of L.A. is covered with impervious pavement.

And this problem of absorption can be readily seen here at USC. McCarthy Quad flooded during February’s record downpours, and because the water did not drain quickly enough, the grass was torn up during the preparation for an event. Now drainage — on a grass field, mind you — is being installed to divert the water that would otherwise just sit there, according to statements from USC Facilities and Planning Management. 

So yes, L.A. has problems, but that’s because the weather is relative. The East Coast will be experiencing flooding as climate change fuels ever more intense storms, and these once-stable rivers will begin to overflow. By 2070, the Charles River will flood over 3,000 acres that do not currently experience inundation due to these more powerful storms.

It’s not that L.A. can’t handle rain, it was handed a different deck of cards. It’s like saying the East Coast can’t handle great changes in elevation. It just doesn’t happen over there.

Climate change is affecting all of us. It’s not just an L.A. problem. It’s everyone’s problem.

Daniel Pons is a sophomore majoring in geodesign writing about USC’s architecture and how it impacts the community. His column, “Walls of Troy,” runs every other Monday.