February 2017 monitoring

February 23 – another unseasonably warm and sunny day. Easily 20+ degrees above the usual 66 degree high (update: it reached 90 degrees). I’m definitely not looking forward to summer, it’s gonna be long and hot!

It rained about 1 1/2″ 4 days ago, so the stream was a bit higher than normal. We noticed some water by the sidewalk under the bridge, possibly from the weep holes in the bridge foundation that allow water to drain. The inflowing water from the parking lot and beyond was still strong, and the short tunnel under the sidewalk was still mostly blocked, so the water was still flowing over the sidewalk to reach the main stream. I confidently say “still” because – as the photos show – algae exactly like that in the main stream is growing over the concrete sidewalk. Note to self: remember to wear waterproof shoes on future visits. (All it should take to clear the tunnel is a shovel, and wearing waders to keep dry feet.)

We heard but did not see birds and there were no pigeons (pigeon poop from when they perch on the bridge supports is one possible reason for higher e-coli count at the site than upstream; it was low this time at both the sample and upstream control sites). Didn’t see any fish or surface algae. The ecoli count at the sample site for 3 ML samples was about 125 colonies (low for an urban stream); the control site upstream was just slightly higher at around 160 colonies for the same sample size.

The stream is slightly higher than usual, enough to have some ripples as it flows over the gravel and stones at the trailing crossing by the sample site – the water sparkled in the sun as it flowed downstream. The 4 bridge pillars are completely in the stream. There was enough water to cover the waterfall, it fell over the small drop with a soothing gurgle. The water was high enough that I didn’t want to walk upstream of the inlet; the “sometime island” rocks in the middle of the stream were just barely uncovered.

Observations:

air temp 19.5 C (67 F)
water temp 16 C (61 F)
dissolved oxygen 8.0
pH 7.0
nitrates .25
specific conductance 430
transparency (dissolved solids) > 1.2 meters

culvert creek flowing into main stream

culvert water over sidewalk

streamside view of sample site and downstream

downstream view of south bank from under bridge

sample site from north bank

under bridge to trail crossing-from-north-bank

streamside view looking upstream under-bridge

submerged trail crossing

under bridge all 4 columns in water

downstream view of under bridge and beyond

stream under bridge

under bridge damp opening and ground

overflow water under bridge

plugged culvert tunnel

upstream view from under bridge

algae growing on wet sidewalk

culvert and wet sidewalk

stream from above culvert

stream from culvert area

waterfall area to culvert

waterfall area

waterfall and above

upstream near sometime island

underwater algae upstream of waterfall

inlet and upstream

downstream view from above waterfall

dissolved oxygen 8.0