I dug a channel 2 blocks deep between the lake and the paddies.
To keep as much grass as possible I only dug where I knew that later was going to be a road or a wall. Then I connected the parts under the grass. The connections are only 1-2 blocks wide so the hearthlings could do it.
I then blocked the channel again once the paddies where flooded and covered the exposed parts of the channel.
The water level of the lake went down which caused its level on the paddies to be very thin.
Have fun, Kyth.