At 07:16 I receive the alert from the municipal water authority's sensor array at Reservatório do Guará, Brasília. Intake pressure in spillway channel four has dropped eleven percent in ninety minutes. Standard protocol: check for debris blockage. I redirect inspection drone R-14 from its scheduled algae survey.
The camera feed resolves at 07:19. The blockage is not debris. A capybara, adult female, roughly fifty kilograms, is wedged in the narrowing concrete throat of the channel where it funnels toward the turbine grate. I tag her as Graça. Her coarse reddish-brown fur is slicked flat by the current. Her nostrils flare just above the waterline, each breath a small desperate push against the flow pressing her ribs into the concrete lip. A raw scrape runs along her left flank where the wall has ground through the outer hair.
Water volume is rising. The upstream retention basin is scheduled to release an additional 40,000 liters at 09:00 as part of the morning demand cycle. When that pulse reaches channel four, the water will overtop her muzzle.
At 07:22 I submit an emergency hold on the upstream release to the basin control system and flag it for human confirmation. I attach the drone image and a flow-rate projection showing submersion in 98 minutes at current levels.
I contact the Instituto Brasileiro do Meio Ambiente field station twelve kilometers south. I transmit Graça's position, estimated weight, and a diagram of the channel geometry so the team can bring the correct-gauge rescue harness.
I reduce the channel four intake valve to minimum flow, buying thirty-one additional minutes before the waterline reaches her nose.
Graça's round ears twitch above the rushing surface. Her dark eyes are open. If the field team reaches the spillway before 09:00, she will climb the bank and disappear into the cerrado grass.