Clogged Pool Drain

The swimming pool's draining system has been acting up again. Whenever I try to lower the water levels, it takes ages for the flow to subside... It's like the tunnels below are blocked again. I told myself I’d call in a technician, but truth be told, I’ve been putting it off. The men cling to that pool like it’s the last scrap of home we’ve got out here. Taking it away, even for repairs, would break morale in half. And yet… there’s something off. A sound, low and constant, like stones shifting under the waterline. Probably a stone or a dead rat, bumping against the pipes. It's probably nothing. Just grit in the filters, I bet. But every night, when the rumble rouses me awake, I can’t shake the thought that something's down there.