noob water/land question

Sorry for such a basic question - in a city-ish melee map I'm working on, I have some man-made canals that go diagonal for abit (using the cityscape textures I believe). Currently, I'm putting up with them being nice and jagged - is there anyway to smooth that out?

Are the cannals made with the cliff tool or the lower terrain tool?

Errr :)

The lower terrain tool, I believe. The one that goes 2 down and makes "deep" water.

that the cliff tool, the cliff tool is the one with the levals, the lower tool is the menbrane with a dip in it, these are just the names i give them. sorry for any confusion.
As its the cliff tool i dont think you can remove the jagedness. if you used a natural cliff type, say grass or dirt then it would look less jages as its naturaly rounded, but it wont look compleataly straight, and probably wouldnt look very good in a city terrain.
All i can think of is using the miscdata.txt to make steap edges without the cliff tool. but to do this easilt youre whole map will have had to have started in shallow water, then raised up. if not then lower the area you want the cannal to be in and all the terrain around it (in a square blocks). then raise the whole map up untill there is no water. then with the lower terrain tool (non-cliff one) make the cannal