This is a note to Phil W. who asked about the reddish, tea-like color of the water in side streams in the Zealand Valley. When I first asked someone the same question years ago about the reddish color (and if was it okay to drink, etc.) I got a brusque answer that it was "the tannin". So your analogy to the tea color is right on as there is tannin in tea. There is tannin in myriad species of plants. The photo above is of a small branch stream of the Zealand River where it flows out of a series of beaver ponds and the water has the characteristic tannin color.
The tannin is leached out of the leaves, stems and other tissues of plants growing in or near the streams and in and around the ponds and lakes that are the sources of the streams. The plant tissues contain the tannin that eventually turns the water the reddish, tea color. If you notice you will see organic matter growing in the stream beds as well as along the stream edges. Last week when I was wading in Zealand Pond looking for Sundews the bottom of the pond had a 6-inch thick "ooze" consisting of organic matter all or most of which contains tannin.
There are a number of factors influencing the presence and amounts of tannin in the water: the water source, the season, the temperature of the water, the amount of precipitation, the flow rate of the stream, and what I call the "Drop Rate." The first five will impact the concentration of tannins in the water. I‘ve observed that more tannin is seen in slow moving streams towards the middle to end of summer and the least in the spring after snow melt when the water is cold and moving rapidly. If it’s a rainy summer with a resulting increase in volume of water and rate of stream flow there's less tannin. The "Drop Rate" effect is when a stream “drops” over waterfalls or down rapids and rills and gets aerated in the process. I’ve observed that the tannin decreases markedly in these streams. I would guess that the air (oxygen) removes the tannin and that there is an inverse relationship between the amount of tannin and amount of oxygen in the water. Phil (or anyone reading this), it might be worth while to Google "tannin" and see what comes up. Thanks for your nice comments, Alex.