Shoreham RNLI Lifeboat Station was called to the incident at about 5pm.
A spokesman for the station said a person had been pulled from the river onto the river bank.
It is believed the person was unconscious and is currently being brought back to the station, the spokesman added.
The volunteer team also attended another incident this afternoon.
Crews said they were called to Splashpoint in East Worthing at about 4pm after man got into trouble in the water.
He was rescued by crews and was left in the care of the ambulance service.
Don’t miss out on all the latest breaking news where you live.
Here are four ways you can be sure you’ll be amongst the first to know what’s going on.
1) Make our website your homepage
2) Like our Facebook page
3) Follow us on Twitter
4) Register with us by clicking on ‘sign in’ (top right corner). You can then receive our daily newsletter AND add your point of view to stories that you read here.
And do share with your family and friends - so they don’t miss out!
Always the first with your local news.
Be part of it.