February 2019

February 17 – today’s high is upper 50s, slightly higher than normal. Two days ago we hit a record high of 91 degrees! Then yesterday with a cold front it was in the 40s and low 50s. Weird, wacky weather.

Last month there was no surface algae. That is still true at the sample site and downstream, where the water is at least a meter deep and crystal clear. But now in the shallow areas upstream of the bridge the surface algae is extensive – it covers nearly the the stream. Yuk. And submerged algae almost completely covers the bottom upstream of the bridge.

It hasn’t rained in a long time and there was an active seep under the bridge that’s fairly new.

The waterfall is down to a trickle along one side of the algae-choked stream. Overall the level of the stream is low – only the downstream bridge pillar is somewhat in the water, the other 3 are dry. And it’s mostly possible to cross the stream with dry feet just upstream of the bridge, but not so much at the trail crossing, despite a few well-placed rocks and a log. Above the waterfall and inlet, the stream is low, and the algae – both submerged and surface – is so extensive that I had no interest in getting close to the visible “sometime island” rocks in the middle of the stream.

Didn’t see any fish (too much algae in the shallow part) or birds. However, there’s a cat lying on atop the bridge supports just under the bridge. No idea how it got there.

The e-coli continues to be low – at the sample site there were only about 15 colonies using a 3 ML sample. The control site by the waterfall had about 50 colonies. Both are well below the acceptable limit for an urban stream.

Observations:

air temp  12.5 C (54 F)
water temp 14 C (57 F)
dissolved oxygen 8.9
nitrate < 0.3
pH 7.0
transparency > 1.2 meters

sample site from north bank

streamside view of sample site and beyond

crystal clear water by sample site

stream under bridge to trail crossing from north bank

trail crossing area

trail crossing from under bridge

stream from bridge to trail crossing

stream under bridge

seep under bridge

low water upstream side of bridge

stream and algae between culvert and bridge

upstream view from under bridge

stream from atop culvert

stream around waterfall area

waterfall and algae

stream and algae above waterfall

dry inlet area

sometime island area

extensive algae underwater near inlet

closeup of algae

downstream view from inlet

dissolved oxygen 8.9

cat under bridge