Unfortunately for non-creatives like me (and perhaps you), I've never found such a service. I have two south river/ocean openings so I just made my river square. I also just flattened most of my town to 1 level as I didn't find any reason to have extra levels. I'll re-terraform when I need location-specific bugs/fish, but I have already caught most all of them. Linkie to my layout
Since they continually update the game, I thought it wise to not over-decorate so I can accommodate as needed. I have a four-star island with little customization...
My real-life time is the same as ACC's