He will also be involved in delivering the high performance satellite programme to players based all over Northland, and will also be involved in player development across the board.
Having Witcombe back working with Ferris meant the pair could establish some continuity - a huge benefit to the pair and the union, Ferris said.
"It's really great, and we're both excited. We really want to try to get out to the far reaches of the province, to make sure we are developing the best players around."
The coach added it was a huge vote of confidence from the board.
"I'm pretty stoked about the challenge and the opportunity ... I think Northland Rugby is heading in a positive direction, with a big focus on development."
A development squad side will once again be established this year, along with an under-20s colts team, while the Harding Shield matches will take on more significance - the inter-zonal clashes will offer club players a chance to impress representative coaches, Ferris said.
Nick Collins will return to the Northland organisation as head trainer and will deliver the ITM cup strength and conditioning programme, and help deliver the high performance programme. Brad Te Haara is club liaison and the Southern Zone development officer. Northland sevens coach Peter Nock will also run the day-to-day running of the development squad.