Again, I can only blame irrational optimism for not thinking we might have some trouble with leaks from streams made out of PVC canvas. Chris and I had done a test on one of the streams, by filling it with water and leaving it outside for a couple of days. When it still held water, we were excited and moved on. But filling 12 streams sitting on bare ground with a precise amount of water was whole different level of testing.
Just as we were wrapping up our set-up and getting ready to officially start the experiment, we noticed water slowly leaching out of about half of the streams and onto the bare ground around them. We had rulers in each stream, so we could see how much the level was falling in each one. There was some banging of heads against the wall (mine), and some reassuring this was an easy fix (Chris), and some general debate about the importance of this factor (all) before deciding we needed to try to patch all the leaks... in our streams already filled with gravel and water.
|David and Emma watching a stream leak|
|David pumping water out of a stream to patch the leak|
|Emma waiting for the silicon patches to dry|