Now, on the 40th anniversary of that film, Netflix and BBC have produced a CG animated Watership Down that closely mirrors it. It is broken down into a mini-series, and features some prominent English actors in some of the voice roles (including John Boyega, James McAvoy, and Ben Kingsley).
I have only watched the first episode, but it's clear that the original film heavily influenced this outing. Some of the voice acting is more subdued than in the original animated movie, most notably Cowslip and Kehaar. I prefer the more bombastic original versions, but I suppose these performances fit better with the more realistic visuals.
Speaking of the visuals, they're not great. The CG animation is a bit sub-par by today's standards, but it's not so bad that it distracts from the story.