Posted by: upperwalnutcreekaustin | January 6, 2020

January 2020

January 5. Five days into the new year and decade. It’s beautiful outside, in the upper 60’s – low 70’s, sunny and breezy… and an extremely high cedar pollen count of over 4,000 (high is around 100). Sniff, sneeze, cough. The wind has been strong enough to distribute the pollen. I’m ready for rain to remove it from the air!

No rain since our last visit, and the stream shows it. The weather has been mostly warm, though a few days were at or just below freezing. There’s now bright green algae around the waterfall, and the submerged algae has increased a lot – there are now long strands around the waterfall. The stream is low enough that water is only flowing over a small section of the waterfall. And the flow from the storm culvert has also decreased. The inlet above the waterfall is dry and plants are beginning to grow, and the “sometime island” rocks further upstream in the middle of the stream are clearly dry.

Downstream of the bridge, by the trail crossing, the stream narrows as it flows past the gravel area, then expands again. The narrow area has a few rocks and a piece of a 4×4 post for walkers to cross with dry feet. If the stream remains like this, I expect the wide part just past the gravel extension will end up rather scummy as the temperature warms, due to it being stagnant.

We saw a couple of turtles by the sample site, and above the inlet upstream there were some water walkers. No pigeons or other birds.

As expected given the lack of rainfall, low temperatures and low flow (not completely stagnant), the ecoli was about the same as last month: for 3 ML samples, the two plates with samples from the control site had  about 16 colonies and the upstream control samples had twice that, or 33 colonies.

Observations:

air temp: 12 C
water temp: 12 C
dissolved oxygen 8.25
pH: 7.0
conductance: 530
transparency: > 1.2 meters
nitrates: < 0.3

 

Leave a Comment

Posted in low stream

Posted by: upperwalnutcreekaustin | December 9, 2019

December 2019

December 8 – a beautiful day. Highs in the upper 60s and sunny. Tomorrow will be a bit warmer, then temperatures drop to the 40s. Welcome to Texas weather.

Since our last visit there has been very little rain and the stream shows it. The water level is low; it would be easy to cross to the south bank just upstream of the bridge. I stood in the middle of the stream to take a couple of photos. Another indicator of little to no rain: the extensive algae. Upstream of the sample site in the shallow water, I was amazed at the algae growth. Last month there was no surface algae and very little submerged algae. Now there was a lot of surface algae (50-75% coverage) and extensive submerged strings.

Further upstream, the “sometime island” rocks in the middle appeared to be out of the water and dry. Although I could have walked up to them with dry feet, I didn’t want to bend double to get under the low-hanging branches that stretched over the stream. And the inlet where I stood had been dry long enough that some greenery was growing.

The waterfall was still gurgling a bit, but water was only flowing over less than half of its width. Water was still flowing down the culvert but not as strongly as last month. And the culvert had a fair amount of (new?) trash in it, along with pools with a scummy surface. Sad. There was also a net bag caught on a branch at the sample site.

Downstream of the bridge by the trail crossing the gravel bar now extends from the north side nearly across to the south bank, so it’s easy to cross with dry feet. There’s only a thin stream that trickles through that spot. Thus, the surface of the water directly below the gravel bar is rather scummy. There’s more trash around there and downstream of the bridge the stream surface was littered with leaves.

Didn’t see any fish, pigeons (pigeon poop is a possible e-coli source) or other birds. And for the first time in a long time, there was no confirmed e-coli in either the sample site or the control site near the waterfall. There were definitely other bacteria, but none were definitely e-coli.

Observations:

Air temp: 16 C
Water temp 14 C
Dissolved Oxygen 7.0
Specific Conductance 570
pH 7.0
Nitrates: < 0.3
Transparency: > 1.2 Meters

 

 

Leave a Comment

Posted in low stream, trail crossing - gravel bar, water quality

Posted by: upperwalnutcreekaustin | November 17, 2019

November 2019

November 16, a gorgeous, cool day. It has rained several inches since the last time we were here. There’s a lot of debris around, both from the previously higher stream and also, sadly, human trash in the culvert.

Someone had placed rocks and a log by the trail crossing so walkers could cross with dry feet. The gravel bar that was between the bridge and the trail crossing (though mostly under the bridge) is still completely gone.

The stream seemed to be a bit higher than last time – on the upstream side of the bridge you’d need to jump a bit to cross the stream. No surprise given the much-needed rain. The higher water level (before today) scoured all of the algae, including all of the underwater algae. All of the algae around the edge of the  waterfall is gone – and the water is falling across the entire width of the waterfall. Even so, the water level upstream of the waterfall was low, so the “sometime island” rocks in the middle of the stream were dry.

We didn’t see pigeons (pigeon poop is a possible e-coli source) or other birds and no fish anywhere, just a turtle by the sample site. The lack of fish isn’t surprising given the chilly water (50 F). The dissolved oxygen was much higher than last time and the stream was crystal clear; there were few to no dissolved solids. This is important as that affects the amount of sunlight that reaches submerged aquatic plants.

E-coli was almost nonexistent. With 3 ml samples, there were about 50 colonies at the sample site and 33 colonies at the upstream control site by the waterfall.

Observations:

air temp: 12.5 C (54.5 F)
water temp: 10 (50 F)
dissolved oxygen 9  (80% saturation)
specific conductance 470
pH 7.0
nitrates < 0.3
transparency > 1.2 meters

 

 

Leave a Comment

Posted in ecoli-low, water quality

Posted by: upperwalnutcreekaustin | October 21, 2019

October 2019

October 20, 2019: completely overcast, which – finally –  kept the temperature reasonable and what it should be given that we’re in mid October. This summer – starting in mid to late July (if memory serves), we’ve had 57 days of 100+. And that doesn’t count the days where it “only” reached 98-99. Temperature-wise, we had an extra month of summer. Yuk. And barely any rain since July, so all that was originally green is now mostly brown. We did have about 1/2 inch last week which helped, but it’s not nearly enough. All of central Texas (and beyond) is well into the exceptional drought stage.

The water was still flowing from the street, through the storm culvert to the stream and even that was a lower flow than normal. In the culvert, some of the pools of water had a scummy surface (as before) and there was more trash on the sides of that inflowing stream.

There was no algae, surface or even submerged. There was scum on the stream surface by the sample site, and a faint smell of sewage. The water was stagnant, with no flow. The waterfall was flowing a bit but only through part of its width. Further up the stream, the inlet was completely dry and even further upstream, the “sometime island” rocks were dry. I didn’t walk up to them though I could have easily done so with dry feet, given the shrunken stream. And I could have easily walked to the south side with dry feet both on the upstream side of the bridge and by the trail crossing, on the latter thanks to some well-placed rocks.

A bit surprising given the lack of flow, there was no ecoli at the sample site and virtually none at the control site above the waterfall. Still no pigeons or other birds (pigeon poop is a possible ecoli source).

The other item of note was the paint on the wall under the bridge: it’s a running battle between the graffiti artists and graffiti “police” painters. One area of the covering gray paint had fallen / been removed and one of the graffiti layers were slightly visible.

Observations:

Air temp 22.5 C
water temp 20 C
Dissolved oxygen 3.7
specific conductance 530
pH 7.0
Nitrate < 0.3
transparency/dissolved solids 1.1 meters

 

Leave a Comment

Posted in low stream, no flow

Posted by: upperwalnutcreekaustin | September 14, 2019

September 2019

September 19, 2019 – or the palindrome 9/13/19 (it reads the same backwards as forwards). It’s actually a bit cooler, finally. 27 of the 31 days of August were 100+ (I’m sure the other 4 just reached 99). So far we’ve had 49 100+ degree days this summer, mostly without a break. I’m definitely ready for fall weather!

We did get an inch of rain 3 days ago, after none at all during the last 6 weeks. The stream has a good flow and is its normal level. I was easily able to walk all the way upstream to the “sometime island” rocks in the middle of the stream with dry feet. I saw some gambusia (minnows) upstream and by the sample site we saw a turtle and more gambusia. Again, no pigeons or other birds – notable since pigeon poop is a possible ecoli source. The water in the culvert/creek that flows from the street is still rather scummy.

The inlet above the waterfall was dry; even so there was enough water that the waterfall had water flowing across most of its length. I was able to walk into the middle of the stream under the bridge on the upstream side as the water easily fit in the small channel near the south bank. This also left the bridge columns with most dry feet.

Downstream by the trail crossing, someone added rocks so that hikers can cross with (mostly) dry feet. The gravel bar that has been there for so many months/years is finally history. It’s been replaced by a muddy extension of grasses by the trail crossing, north bank. The recent rain also turned everything green. I noticed that some plants have grown noticeably. However, in the stream there was no surface algae and very little submerged algae.

This was the first time the water in the bucket wasn’t completely clear; it had a definite yellowish cast to it. Possibly this was due to the dissolved solids from the recent rain.

This site has always had gang activities; the wall under the bridge often has graffiti that is eventually painted over. Then more graffiti is added which is painted over… This visit we also noticed something else: about a half  dozen needles left on the rocks by the sample site.

E-coli at 3 ML averaged 100 colonies at the control site and 232 colonies at the sample site. Acceptable for an urban stream.

Observations

air temp 26.5 C
water temp 25.5 C
dissolved oxygen 4.5
pH 7.0
specific conductance 454
transparency .85 meter
nitrates < 0.3

Leave a Comment

Posted in trail crossing

Posted by: upperwalnutcreekaustin | August 12, 2019

August 2019

August 11 – one more hot and humid summer day in Texas. For the last week the temperatures – excluding humidity – have been at or over 100. Add another 5-8 degrees for the humidity effect and in a word, the result is: miserable!

Eight days ago it rained about .2″, and not at all for a week or so before that. So the stream is its usual sluggish summer self. Someone added rocks at the hiking trail to allow walkers to cross with dry feet. The stream is so low there’s no current (flow) at all, it barely trickles through the rocks at the hiking trail. Much further upstream above the waterfall the “sometime island” rocks are dry – I was able to easily walk up to them with dry feet. And it would be very easy to cross to the hike and bike trail upstream of the bridge. Due to the low water and no flow (at least in part), there’s a lot of scum on the surface around the sample site. Not sure what the rest of the reason is for all the scum.

The flow through the culvert (from the street) is lower than usual, and parts of the water flowing through the culvert are very scummy, as well as somewhat trashy.

The surface algae has reappeared… and much of it near the edge of the stream is dying since the stream has shrunk.

I saw a school of gambusia (minnows) above the waterfall, and we also saw an egret by the sample site. Otherwise, there were no pigeons or other birds, and no other visible aquatic life.

For the first time in memory, the water temperature of 27.5 C (81 F) was slightly higher than the air temp, 26.5 C. No surprise, the dissolved oxygen was much lower – warmer water holds less oxygen than does cool water. Why? per a chemist, in warm water the oxygen molecules have more kinetic energy (they move more) so the gas molecules in hot water can more easily overcome the weak binding forces within water and escape through the surface.

Despite the lack of current that would move microbes, the e-coli count was very low: 16 colonies on a 3 ML  sample.

Observations:
air temp: 26.5 C
water temp: 27.5 C
dissolved oxygen: 3.25
specific conductance 540
pH 7.0
transparency .96 meters
nitrates 0.3

 

 

 

 

Leave a Comment

Posted in low stream, water quality

Posted by: upperwalnutcreekaustin | July 13, 2019

July 2019 Monitoring

July 12 – another hot and humid day. It’s “only” in the mid to upper 90’s per the thermometer but thanks to the humidity, the heat index is well over 100. We’ve had a very wet summer so far (among other things, the lakes are completely full, which is unusual this time of year). So we haven’t hit 100 yet – very unusual for July, but so is all this rain and humidity.

With all the rain, the word for this summer is Green. All the plants – grasses, trees and more – are growing much more than usual in the summer.

Walking down to the stream we noticed a lot of trash in the creek that flows down that culvert next to the path. With nearly 2″ of rain in the last 2 weeks, guess that’s not surprising. Just sad. And the surface of the creek in the culvert is very scummy.

Also thanks to the recent rains, there is virtually no algae at all, either surface or submerged algae. There are a few clumps starting to grow here and there, but very few. I did see a school of gambusia (minnows) above the waterfall and inlet. The “Sometime Island” rocks in the middle of the stream above the inlet appear to be at least partly covered, I couldn’t get close enough with dry feet to confirm. And the water is flowing across the full length of the waterfall.

Downstream of the bridge, someone placed a few rocks in the the trail crossing but they’re not enough to prevent wet feet when crossing the stream.

Didn’t see any pigeons (pigeon poop is a possible e-coli source) or other birds… and for the first time ever there were NO e-coli colonies in the 3 ML samples on either the control or sample sites! Maybe the frequent rains washed them downstream? (But what about further upstream colonies flowing down to this site?)

Observations:

Air temp: 28 C
Water temp: 26 C
Dissolved oxygen 5.0
Specific conductance 450
pH 7.0
transparency (dissolved solids) 1.15 meters
nitrate < 0.3 mg

 

 

 

 

Leave a Comment

Posted in recent rain, trail crossing-wet

Posted by: upperwalnutcreekaustin | June 20, 2019

June 2019

June 19 – it’s (finally) starting to be a typical Texas summer. For the last few weeks it’s been rainy, cloudy and relatively cool – the humidity wasn’t too bad given the highs in the 80s.  But now it’s summertime, with highs in the upper 90s/100 and humidity not far behind. Yuk.

Since our last monitoring session it has rained nearly 3″. Thanks to all the rain, both the stream and the waterfall are flowing well. And sadly, there’s a fair amount of additional trash in the culvert – at least it gives an idea of how much rain we had at a time. Likewise, we saw a bit of new trash on one of the exposed rocks just upstream of the bridge. We also saw a school of gambusia (minnows) above the waterfall and a few close to the sample site. Also thanks to the rain, there’s no surface algae and only small clumps of submerged algae. And above the waterfall and inlet, the “sometime island” rocks in the middle of the stream appear submerged. I couldn’t get close enough without wet feet to see them.

The trail crossing area is completely wet, there’s no rocks there so crossing the stream requires wet feet. Even the upstream side has too much water to cross with dry feet. And the gravel bar that has existed on the downstream side for many months is nearly gone,  it’s just a shadow of its former self.

Still no pigeons or other birds at the site (pigeon droppings are a possible e-coli source). E-coli continues to be at an acceptable level for an urban stream. With 3 ML samples, the control and sample sites both averaged just below 100 colonies.

Observations:

air temp: 27.5 C
water temp 25 C
dissolved oxygen 6.7
pH 7.0
specific conductance 370
nitrates < 0.3
transparency (dissolved solids): 1.2 meters

Leave a Comment

Posted in trail crossing-wet, water quality

Posted by: upperwalnutcreekaustin | May 20, 2019

May 2019 Monitoring

May 19: after at least two weeks of on and off rain – and flooding – it’s been sunny for a few days. And now the temperature is getting close to (and above) the usual highs. And it’s HUMID! Yuk. It’s also incredibly green, thanks to all the recent rain. Wonder how long that will last?

Saw a turtle perched on a partially submerged branch by the sample site and another swimming nearby. Both hurriedly left when spying us. No pigeons or other birds in sight or earshot.

The stream was flowing stronger than normal thanks to the recent rains and there’s no surface algae. There’s enough water flow to span the entire waterfall length (width?). The stream is high enough that someone wanting to cross from the north bank to the south bank would have to get wet feet. There are no stepping stones any more by the trail. And the gravel bar that has been on the downstream side of the bridge is mostly gone.

The water was apparently much higher at some point as we saw some fair sized branches close to the sidewalk, which are about 20 feet from the current stream, as shown in the pictures. There also is some new debris in the culvert that drains from the street level.

E-coli: there were 116 colonies at both the sample and control sites based on 3 ML samples. Within acceptable limits for an urban stream.

Observations:

Air temp 26 C
water temp 23 C
dissolved oxygen 7.4
specific conductance 560
pH 7.0
nitrates 0.9

 

Leave a Comment

Posted in recent rain, trail crossing-wet, water quality

Posted by: upperwalnutcreekaustin | April 15, 2019

April 2019

April 14, an absolutely gorgeous day! Sunny and cool, quite a change from yesterday’s morning rain and late afternoon high winds, gusting up to 50 MPH.

The stream was clear, especially given yesterday’s rain of about 1/3 of an inch and a week ago 4 inches of rain in one day. The resulting flow from that heavier rain was enough to remove all the surface algae and much of the submerged algae, which has begun to regrow. It also completely eliminated the remaining gravel bar in the stream under/downstream of the bridge and removed the rocks someone placed in the water by the trail crossing so hikers could cross with dry feet. Now to cross requires wading.

The stream is slightly higher than last month, and water is noisily flowing over the full width of the waterfall, rather than over just a part of it. The stream extends a bit into the inlet above the waterfall, and it looks like the “sometime island” rocks further upstream are covered. And just upstream of the bridge it’s not possible to walk to the other bank with dry feet unless you can do a long jump. Even so, two of the bridge columns are completely out of the water. The stream’s main channel is now between them and the south bank, as it has been since the construction for the hike and bike trail.

We saw a school of gambusia (minnows) in the shallow area near the sample site and trail crossing. No pigeons (possible e-coli source) or other birds. The “cat” that we’ve seen the last 2 visits sitting atop the upper bridge supports was still there. A passerby said it looked more like an owl with tufted ears – it’s high enough that due to the angle of sight its body isn’t visible. That makes more sense, I’ve always wondered how a cat could climb the vertical concrete pillars to reach that perch.

The e-coli 3 ml sample at the site had 166 colonies, the control site above the storm culvert was slightly higher at 233 colonies.

Observations:
air temperature 15.5 C
water temperature 15 C
dissolved oxygen 8.5
specific conductance 490
pH 7.0
Nitrates < 0.3
transparency 1.1 meters

 

 

Leave a Comment

Posted in recent rain, trail crossing-wet

Older Posts »

Categories