Moving water is going to have some specular highlights in it -- reflections of the sun that go pure white. It give the water some sparkle. Have you tried printing the first roll yet? What kind of enlarging set up -- condenser -- cold light?(posted 9094 days ago)Make a "proper proof sheet" where you expose the paper until the clear film edges JUST match the black of the paper with no film over it. That will show you how the negs will print through a cold light enlarger.
If you still think they are too contrasty, try multiplying the original developing time by 0.7. That ought to move the highlights down about a stop lighter. Dont change anything else in your procedure. The agitation sounds right.