Creating a map for my novel

[waldronate]

Without a scale it's hard to tell precisely what's going on, but the number of water channels and multiple cuts on the lake suggest to me that the area is a tidal marshland and the whole map is about 3-5 miles across. Larger areas would tend to have a somewhat less dense and less randomly-oriented flow network.

The attached image shows what happens when finding the flow pattern for a simple valley. The amount of noise relative to the terrain is increased, effectively reducing the slope fo the landscape. At first (noise=0), the rivers follow the terrain exactly. When the noise is much greater than the terrain (noise=10 meaning that the noise is by far the dominant factor and the land is effectively flat), the rivers don't follow any sort of pattern except a general outflow at the valley exit. Noise=0.01 corresponds roughly to a stone valley, while noise=10 corresponds roughly to a tidal mud flat.