Wow. That’s beyond impressive. Good for inspiration. Now have to find out the mechanics. I am sure (pretty sure) that it’s the basic pond garden. But I am curious about lining the feature and if you can indeed make scale (ish) rivers, etcetera...how much flow is required and such.
Water feature creation is a pretty large subject, s Hobby in its own right in fact.
Certainly for a good feature the best Liner you can afford works, Butyle is what you need. The Pond itself could be a preformed One but these can be a bit tricky to disguise and make natural, if you go that route it should be a Black one. Digging the hole can also be a big job but the excess soil can be used for say a Water Course if you have the space. If you do a Water Course line the sides with bricks to make a ravine then put in Liner over the bricks and cover that with Rocks do not forget the Underliner to protect your Butyle. Those Rocks can be held in place with cement or joins disguised by smaller rocks and pebbles. Any Cemet used near the Water if Fish are involved should be sealed with G4 to protect them from Cement Chemicals. Now for your pump, this can be tricky to work out as distance covered to the top of your Water Course and height lifted can both effect the Water Flow. Do you want a Torrent of Trickle?
Much of this advice can be confirmed with a Good Pond Supplier, do not use a Major DIY Store to get the bits as they will not be able to give expert advice. A Fish Stockist, Koi Stockist will also be able to help I find them to be very interested in whatever your project is and may even be able to do it for you if your Budget extends to that.