June 2017

June 18. We may yet reach 100 again, just like yesterday. Yuk. It’s hot and humid with no recent rain and the stream reflects that – very low flow (nearly none) and extreme algae coverage. I was surprised how much the algae had grown since our visit last month. And this time the surface of the sample site is definitely scummy. Yuk.

Heard a few birds but didn’t see or hear any pigeons (a possible source of e-coli). We saw numerous fish, both a few that were 4″ – 8″ and a school or two of gambusia (minnows). The waterfall was down to a trickle in the middle, I could barely hear it. And it was completely caked with algae, including in dry spots where the stream had shrunk. The flow from the culvert, which brings water from the parking lot and street, is also lower than usual. A close inspection of the culvert on the upstream side of the sidewalk showed that the “tunnel” entrance under the sidewalk is completely clear now, and that there are some fairly good-size rocks sitting just in front of the tunnel. Another heavy rain/flow down the culvert may move them into the tunnel, thus making it a bit easier for the tunnel to again be blocked.

The stream was low enough that I was able to walk not only to but beyond the “sometime island” rocks in the middle of the water a bit of a way upstream of the waterfall. And much closer to the sample site, by the trail crossing immediately downstream of the bridge the stream was so narrow it was easy to cross it with dry feet.

One good note: the e-coli counts (3 ML samples) were reasonable for this site – under what is expected for an urban stream. And the counts were similar at both the sample site and the control site which by the waterfall, upstream of the inflowing culvert, which adds water from the parking lot and street (including people and pet pollution).

Observations:

Air temp 29 C (85 F)
Water temp 26 C
Dissolved Oxygen 4.4
Specific Conductance 620
pH 7.0
nitrates .75

sample site from north bank

downstream of sample site scummy water

sample site scummy water

sample site from streamside-scummy

stream from bridge to sample site from north bank

stream w algae from bridge to trail crossing

trail crossing area from streamside

tiny stream by trail crossing

closeup of stream between bridge and trail crossing

downstream view from under bridge

upstream side of bridge

upstream and south bank from under bridge

culvert on upstream side of sidewalk – freely flowing water and rock possibly blocking it

upstream view from under bridge

view from above culvert

stream between culvert and bridge

closeup below waterfall

waterfall area and below

upper stream above waterfall

stream directly above waterfall

closeup of waterfall area

stream above sometime island area

closeup of algae above waterfall

dry inlet above waterfall

downstream view from by sometime island rocks

dry sometime island rocks and beyond

dry sometime island mid stream rocks

stream above inlet

dissolved oxygen 4-4