November 2017 monitoring

November 18 – the wacky warm weather continues. It reached another record high of 84 degrees today after we monitored then in mid afternoon the north winds gusted in and the temperature started dropping. It was a much more reasonable 71 by late afternoon, and dropping even further as the sun set. The next day, as I checked the e-coli samples, the temperature was a more reasonable, albeit chilly, 52 degrees.

Despite no recent rain, the stream was in good order – all 4 bridge columns were standing in the stream, and directly on the upstream side of the bridge the stream completely filled the main streambed  so it wasn’t possible to cross without wet feet. On the downstream bridge side, the flow diverged into two small channels (as it has for some time now), so that it is possible for people to hike across the stream with dry feet. And a final note on the level: the inlet above the waterfall was completely dry as were the “sometime island” rocks in the middle of the streambed further upstream.

The water flowing from the culvert had a good flow, despite being still blocked by branches and other debris and hence has a somewhat scummy section (same as last month). Enough water percolates down through the block to keep a good flow into the main stream.

The waterfall is flowing in the middle section, same as last month. There are some rather dry rocks in the streambed immediately above the waterfall and there is a fair amount of surface algae, definitely more than last month. And upstream, the water is low enough that the mid-stream “sometime island” rocks are dry and it’s possible to walk past that point.

Saw a school or two of gambusia (minnows), did not see or hear any pigeons or other  birds. Why mention pigeons? In the past, when pigeons were roosting in the bridge supports, their droppings may have contributed to higher e-coli counts downstream. Currently the e-coli counts at both the sample and control site by the waterfall were well within acceptable levels for an urban stream – for 3 ML samples, 183 colonies at the sample site and slightly less for the control site.

Observations:
air temperature 24.5 (76 F)
water temperature 21.5 (70.7 F)
dissolved oxygen 4.5
specific conductance 560
pH 7.0
Nitrates 0.3
Transparency > 1.2 meters

sample site from north bank

sample site and downstream from streamside

downstream view of trail crossing and beyond

under bridge to trail crossing

stream under bridge to trail crossing from north bank

closeup of channels under bridge

under bridge view from upstream2

downstream view of south bank from under bridge

trail crossing area closeup

stream from atop culvert

stream above waterfall

stream directly above waterfall

stream above inlet

sometime island rocks area

low water above waterfall

dry sometime island rocks

dry inlet and low stream above waterfall

closeup of stream with leaves above inlet

downstream view from above inlet