So I figured out how to make a water plane which was surprisingly easy!!! Except...... it's not where I want it to be. I did input the Y axis into Zaide_Chris's Sims 3 Standalone Water Plane Generator, used the trees to measure, double checked the height map is correct. I'm honestly just not sure what I'm doing wrong! I've attached some pictures for reference.

I'd attach the .bnry files but I'm also not sure how to do that on here, so if it'll help please let me know! Thanks in advance (:

What I always did was to place an object, for example a streetlamp, at either corner of where you want the water plane. Then you have your x,y and z positions correct to plug into the program. You could also try Sandrine's program:
http://www.modthesims.info/showpost...56&postcount=25

That's what I did, i used some trees.

What value did you enter? Was it between 0 - 300? And did you use a . (point) as decimal separator (not a comma)?

As I can't see if you did this from your pictures, make sure you lower the terrain a little underneath the waterplane, especially where the center of the plane is, else the water plane will vanish into the ground. The waterplane should be enclosed by terrain.

I did use a decimal point! So I should be using a comma then? The value is correct, I used 300 on my 300 height world.

No, a point as decimal separator is correct. But using 300 for height (y) explains it all: of course your plane would be at height 300, i.e. at the top of your world box. Use the height of the tree you used as reference, maybe a bit lower so that the waterplane sits lower than the surrounding terrain.

OHHHH wait hang on. So in Zaide_Chris's generator I put the y axis as 73.84443. In the 707 generator it asks for the altitude, which I put as 300. Are you saying I should switch that 300 number out for the 73.84443? If so that makes so much sense, silly me!!!

Yes, altitude in Sandrine's 707 generator means also height of the waterplane (y), not of the world. There you go!