May 2018 monitoring

The morning of May 19, 2018 was in the Goldilocks zone – not too hot, not too humid. Just right. It was overcast as we monitored; soon after the sun broke through the clouds.

With no recent rain, the stream is lower than it has been in several months. We had a couple of inches of rain soon after last month’s monitoring but no real rain since, despite May historically being one of the wettest months. The upstream bridge column’s base is out of the water, and the other 3 barely have wet feet. The inflowing culvert still has a good flow, though there is some new trash caught in its branches, probably from that rain. There’s also a fairly substantial pool in the bottom half of the culvert that has a scummy surface.

The trail crossing is dry – looks like someone(s) has extended what’s left of the gravel bar by adding rocks so people can easily cross with dry feet. The drawback is while the water level is this low this has mostly stopped the stream’s flow; only a trickle gets through. Ma Nature will probably fix that during the next heavy rain. Thanks in part to that, the downstream sample site’s surface is somewhat scummy. We didn’t see any aquatic life at the sample site; I did see a school of small gambusia (minnows) upstream of the waterfall and inlet.

The waterfall is still running and gurgling but the flow is much reduced from last month. The inlet above the waterfall is completely dry, and the “sometime island” rocks in the middle of the stream about 50 ft above the inlet are completely dry. I was able to easily walk up to and even past those rocks with dry feet. Although there’s no algae downstream of the bridge, there is a lot of surface and submerged algae upstream of the bridge, around and above the waterfall and inlet. The submerged algae is still in clumps. It hasn’t yet grown the long strands. Maybe by next month.

Still no sign of pigeons (a possible source of e-coli at the sample site). We heard one noisy bird and saw a heron sitting on the rocks near the waterfall. It calmly watched us work for several minutes then flew away.

The e-coli was basically absent – with 3 ML samples (2 petri dishes each for the control and sample sites), one dish each had 1 single colony – we’ve never seen it that low.

Observations:

Air temp 25.5 C
Water temp 24 C
Dissolved oxygen 3.85
Specific conductance 510
pH 7.0
nitrate < 0.3
transparency (dissolved solids) 1.14 meters

 

sample site from north bank

sample site-scummy surface

view of stream from north bank

trail crossing from downstream

trail crossing

downstream view from under bridge

under bridge one dry column

upstream view from under bridge

stream from culvert to under bridge

trash in culvert stream

scummy culvert pool

stream from above culvert opening

stream around and above waterfall

waterfall area and below

heron by waterfall

dry inlet above waterfall

algae above inlet

low stream above sometime island

downstream view from above inlet

stream above inlet

dry sometime island rocks

downstream view from above sometime island

dissolved oxygen 3.9