If you've unlocked the ability to change the terrain and waterways on your island in Animal Crossing: New Horizons, you may be wondering how to cut diagonal riverbanks and shave sharp sides off cliffs. There's no specific 'diagonal cut tool', but it's easy when you know how and it will enable you to build bridges at an angle, too.
Firstly, you'll need to unlock the Island Designer app on your in-game NookPhone. This involves attracting new residents to your island and having K.K. Slider give a concert. Once this has happened, Tom Nook will send you the new app for your NookPhone which enables you to transform the terrain of your island and construct intricate waterfalls, fill in ponds and redirect rivers to your heart's content.
How to cut diagonal riverbanks in Animal Crossing: New Horizons
Cutting a diagonal riverbank involves understanding how your island is divided into an invisible grid of 'squares' and it's worth experimenting before embarking on some intricate river sculpting or terraforming project.
As we said above, there is no 'diagonal cut tool' with the Island Designer app. Instead, cutting diagonal riverbanks and putting curved edges on cliff and paths requires you to 'shave' hard edges off of stepped river banks. It's all explained below with pictures...
Firstly, find the river bank you want to alter, open the Island Designer app on your NookPhone and select 'Start Construction'. Press '+' and select the 'Waterscaping Permit' if it's not already equipped (this can be purchased from the Nook Terminal in Resident Services for 6,000 Nook Miles).
In the pictures below we've cut out a nice flat bank to demonstrate how it works. Approach the flat bank and press 'A' while facing the water to shovel material into the water and 'fill in' a square of riverbank like so:
Fill in the square next to it so you have two complete 'blocks' of land jutting into the water:
Position yourself aiming for the first block again and press 'A'. You'll notice that rather than scooping out a square of land, the pointed edge is carved into a smooth diagonal line:
In order to make a long, straight diagonal line, you'll need to fill in the land to create a stepped, 'jagged' edge like so:
Once you have this, work your way along the steps and press 'A' to cut each one off at a 45° angle. Don't worry if you accidentally dig a square out entirely - simply fill it in and start again. Work your way along and voilà: you've got yourself a diagonal edge!
It takes some trial and error to get to grips with exactly how the game handles diagonals, but with practice it soon becomes second nature and you'll be cutting intricate waterways and waterfalls with ease.
It's worth noting that the game won't allow you to have two opposing diagonals next to each other - you can't create a 'point' with diagonal cuts without separating them with a 'straight'. Attempting to cut a diagonal right next to another (as in the first picture below) will result in the entire new bank disappearing; the second picture is the closest you can get (although you are able to build into the river off that 'straight'):
Using this method, it's possible to build bridges over rivers at 45° angles (speak to Tom Nook for infrastructure plans and to choose the type of bridge you want). The river must be the correct width and totally smooth on both banks, but you know how to achieve this now using the Island Designer App. The river in the pictures above is too narrow for a bridge, but here's one we made earlier:
And that's it! This technique of 'shaving' the edges off right angles can also be applied to cliff edges using the Cliff-Construction Permit, and the same principle also applies if you want to give your custom paths curved edges, too.
Have fun experimenting and don't worry too much about making mistakes. Nothing is permanent when it comes to terrain in New Horizons; everything can be fixed, altered or returned to its previous state, so feel free to go mad with your grand designs.
This article is part of our Animal Crossing: New Horizons walkthrough, which covers How To Fish with Complete Fish List and How To Catch Bugs with Complete Bug List. If you're looking for specific fish we can tell you how to catch the elusive Coelacanth, Mahi-Mahi, Giant Trevally, Stringfish and Golden Trout, along with a list of Fish And Bugs leaving at the end of June and the Best Custom Design Codes and Islands we've found so far. We can also help with How to Spot Redd's Fake Paintings and Statues, How To Make Bells Fast, How to Breed Flowers, How To Get More DIY Recipes, How to Upgrade Nook's Cranny, plus tips on using the Star Wand, Tool Ring, Rock Trick, Cutting Down And Moving Trees, and using amiibo on Harv's Island.
And finally Where To Buy Animal Crossing: New Horizons On Nintendo Switch if for some reason you haven't yet picked up the game.