keep up

The NRA is pumping groundwater into the River Itchen in Hampshire to keep up its flow and is trying to save three streams, the Tong, the Little Stour and the Dour from going dry this summer.

Keep up the good work of entertaining your fans on court Steffi; we know you can do it; your fans are behind you all the way.

They ran so fast I could hardly keep up.

I always try to keep up with (or "keep up on") current affairs.

The crying baby kept me up all night