Evaluate the consequences of loosening fish distance critera

[limnoliver]

While figuring out NGWOS data (#29), I loosened the fish distance criteria from 5k to 20k. We use the absolute value, such that we're not distinguishing between whether a site is coming from upstream or downstream of the end of the segment. Should we change our criteria based on upstream downstream? I don't think so, but wanted to flag this as a potential issue. Here's an example of two reaches that have multiple sites that have big fish distance. Are we okay accepting a site that is really far downstream of a segment end? Note in the past, those red dots far down the blue segment would have been dropped, and likely the blue dots in the mid blue segment as well.

[jzwart]

One potential issue with absolute values for fish distance would be if there is a confluence immediately downstream of the end of a segment - sites downstream of the confluence might not represent end of the segment very well.

[limnoliver]

Yes, good point Jake, and I would bet that many of the points of interest that were used to delineate reaches in the geospatial fabric were confluences.