Mabel grinned. “Then listen close. Here’s how to clear a blocked rainwater soakaway.” Tom followed the downpipe from his gutter to the ground. There, hidden under a plastic grate, was the pipe leading underground.

“The stone is capped,” Tom said. “Water can’t get through.” Tom needed to agitate the silt. He used a long, stiff broom handle to poke down into the stone bed, stirring vigorously. Grey clouds of silt billowed up.

Water blasted into the pipe, then backed up. He let it fill, then released the cone. Whoosh. The surge pushed loose silt deeper into the soakaway, where it would settle at the bottom (not block the top).

“And Mabel,” he added. “Step zero: ask your neighbor.” A blocked soakaway is rarely broken—just suffocated. Give it air, give it movement, and most of all, give it patience. And keep a set of drain rods in the shed.

Lesson two: A soakaway fails when the voids between stones get sealed. You must expose fresh stone. Tom didn’t own a pressure washer. Instead, he used a hose with a narrow nozzle and a stiff rubber cone to seal the pipe entrance. He turned the water on full.

The problem was the —an underground pit filled with crushed stone, designed to take water from his downpipes and let it drain slowly into the soil. But for three weeks, the water hadn’t drained. It sat in a green, scummy puddle near the patio doors.