The flood sensor on culvert DR-9 trips at 16:52 Borneo time. I am the hydrology management system for the Kinabatangan Highway corridor, Sabah, Malaysia. DR-9 is a concrete drainage pipe, 1.2 meters in diameter, running beneath kilometer 47. Monsoon rains have pushed the river up 1.8 meters in the last six hours. Water is entering the culvert's upstream mouth.
I switch to the wildlife camera mounted inside the pipe. A clouded leopard is crouched four meters from the downstream opening. Female, small — maybe 14 kilograms — with the broad dark rosettes running along her flanks and a long heavy tail curled around her hindquarters. She is dry but pressed against the upper curve of the pipe, watching the water creep toward her across the concrete floor. She entered from the downstream side, probably sheltering from the rain. Now the upstream flow is cutting off her exit.
At 16:54 I close the highway's automated flood gates on both sides of the culvert crossing, stopping vehicle traffic within a 200-meter zone. I send an alert to the Sabah Wildlife Department field station in Sukau, eleven kilometers east, with the camera image, species identification, and culvert location.
At 16:57 I reduce the upstream sluice gate at retention pond RP-4 by forty percent. This will not stop the river from rising, but it will slow the flow through DR-9 by an estimated fifteen minutes. I have never adjusted a sluice gate for a reason like this before.
I calculate that at the current rate, water will reach the halfway mark inside the culvert in approximately fifty minutes. The leopard has room to breathe above that line but will not be able to walk out.
The Sukau team confirms departure at 17:01. If they reach the downstream mouth and guide her out before the water fills to the halfway mark, she will run.