🌾 What was here before the farms?

Far away in California, two big rivers meet in a place called the Delta. The Delta is a giant maze of rivers and islands, all tangled together. So what was there before the farms? Meet the tules. Tules are tall, grassy plants, taller than a grown-up! Long ago, tules covered the islands like a big green carpet.

Every day the water rose and fell around them, like a bathtub filling and draining. Then people came who wanted farms. They built long walls of dirt, called levees, to keep the river out. Then they pumped the water off the land. But the soft, spongy ground dried out and sank way down! Can you guess how low?

Lots of fields are now lower than the river beside them. The river peeks over the wall like a nosy neighbor: hello, carrots! Today the levees still hold the water back from the farms. And tules still grow along the edges, waving at the boats.

Far south of Canada, in California, two big rivers called the Sacramento and the San Joaquin meet and tangle together. That tangle is the Delta, a maze of islands and winding water covering about eleven hundred square miles. So what was there before the farms? Let's follow one handful of river mud to find out. When the ice age ended, the sea level rose. River water carrying mud rushed toward the ocean, but it had to squeeze through one skinny gap called the Carquinez Strait, the only way out of the whole Central Valley.

Because the gap was so narrow, the mud piled up like cars jammed at a one-lane bridge. Our handful of mud settled into an island, and tall reeds called tules, said TOO-lees, grew on top. Here's the surprise: when tules died in that soggy water, they didn't rot away. They squished into a spongy soil called peat, for thousands of years. Think of it as very old, very flattened salad. Then people came, built walls of dirt called levees around the marsh, drained it, and planted farms on the peat soil.

But draining the peat made the islands sink. Here's a guess for the car: standing in one of those fields, would you look up or down at a passing boat? Up! Many Delta farms now sit lower than the rivers right beside them. Only the levees hold the water back, guarding fields that grew from a marsh of reeds.