A few photos and notes

While I'm working on some longer posts .....

It's 50° F. and Little Dry Creek is capped with ice. That emphasizes Ice's floating and insulating qualities, some of the properties that makes water so important for life on this planet.

There's a new art installation at Holly Reservoir sponsored by South Suburban Parks and Recreation. "Dichro Rings", by Evan Beloni, is constructed of dichroic materials that reflect light at different colors according to the angle they are viewed. Beloni also calls them "Dichrolions".

I had to pick up a prescription from the King Soopers down the hill on Arapahoe so I turned it into a hike. I often take Little Dry Creek trail to avoid the traffic. It passes by Holly Reservoir. On the way back, I tried out a different approach to Englewood Dam, along South Homestead Parkway.

If you have time, you might walk and turn your errands into hikes 

Little Dry Creek: The Grand Tour

I've mentioned that I like following waterways from beginning to end. I've finally gotten around to following the neighborhood stream, Little Dry Creek, from it's head near Yosemite and Arapahoe, to it's mouth near Dartmouth. I almost finished early enough to photograph the river end but, alas, it was quite dark when I got there.

I started at the spring behind the Safeway offices. Everything above that is runoff.

My elevation was 5720 feet according to my topographical map. Air temperature was 74.7° F so I was shedding clothes. The stream water was at 3.5° C. It was coming directly from the Dawson formation so it was cold. I'm flip flopping between Fahrenheit and Centigrade because most weather is reported in Fahrenheit but I like to know how far above freezing things are. Water freezes at 0° C.

I tried to get an idea of the flow rate when I took samples for later analysis. I measured approximately average depth and width and tried to clock a piece of balsa wood floating downstream. But the wood wouldn't move. The flow rate at all three sites was "a trickle". I know that the water was moving because it was flowing over the weirs 

The stream here was two inches deep and 12 inches wide.

The Dawson aquifer isn't very productive and having watched the flow rate recorder by the gauge near Arapahoe (It has been nonfunctioning for a couple of months now) and keeping an eye on the spring, it looks like the flow rate responds to rain fall and snow melt almost entirely. 

A network of runoff channels between Yosemite and Alton Way carry Stormwater into Little Dry Creek for and initial boost. The creek shows a good start at valley building.

This view is just west of Yosemite from the spring at the beginning of the Little Dry Creek Greenway. From here on, rocks and weirs (overflow dams) have been added to the bed and shoulders to manage erosion.

Any large rocks in the area are primarily brought in for landscaping and erosion control, so this is not a good area for studying the indigenous bedrock. The top soil is shallow and the underlying material is clayey, weathered bedrock. The bedrock is colluvium, the pulverized material washed out of the Rockies that filled the Denver Basin in recent geologic times 

My second sampling site was between Little Dry Creek Park and Uinta Street. The banks of the stream are steep and there are several slumps where gravity is pulling chunks of the bank into the creek. Closer inspection show these slumps to be saturated with water. They look like seeps, slow moving springs from the underlying Dawson aquifer.

There was a small slump that was just big enough for a foot and a knee. I knelt on that to take a temperature reading and water sample. The temperature was 6.6° C. Trying to stand, I overbalanced and went in head first.

I came out really quickly 

Little Dry Creek is polluted and smells bad. I hoped that the rest of the ten mile hike would give me a chance to dry and air out. On the train back home, no one looked particularly offended so it must have worked.

The water here was 3 degrees warmer than at the spring. I would be tempted to credit that to kinetic energy of flow but it probably had much more to do with the amount of surface area exposed to the sun. The creek was 50 inches wide there. The depth was 14 inches (just enough to totally submerge me and make me actually swim to get out.) Air temperature was down from the spring....68° F., about 7 degrees colder.

This was where I gave up trying to measure the flow rate by throwing chips of balsa into the water. There was flow. Water was trickling over the weir downstream, but the surface was dead calm. There was an active storm sewer dumping into the creek upstream and the aquifer was adding volume at the seeps.

The creek is geologically young but the material under it is clayey debris and crumbly arkose sandstone so it has no problem cutting into it. The whole length has vertical banks from 2 to over 20 feet high, moderate meanders, and a broad valley.

Here's a topographic view of the first quarter of the course of Little Dry Creek from "Highlands Ranch Quadrangle, Colorado, 7.5 minute series." If you're not familiar with topographic maps, the brown lines are elevation contours. The closer they are, the steeper the incline. The v-shaped contours around the creek point upstream.

One advantage of this hike is that it follows a creek that's flowing downhill. There's not a lot of "up".

The third (and last) sampling site is a pretty little cascade just before Spruce Street. It's not "natural". Those granite and gneiss boulders were artistically placed there by Parks and Recreation workers. They did a nice job. A culvert empties an intermittent tributary into Little Dry Creek below where I sampled. (See the blog "Walnut Hills: The Big Hill")

Little Dry Creek was colder here (3.4° C), almost as cold as at the spring. That's interesting since the air was warmer (68.2° F) than at the second site. And I would have expected those rocks to have been soaking up sunlight and transferring the heat to the water.

The stream was 112 inches wide here and 16 inches deep. Of course, the stream dimensions can change but there was no reason for big fluctuations Little Dry Creek is historically pretty consistent, so it's reasonable to compare them from site to site. Within about half a mile, the stream has more than doubled. Runoff isn't large so I'll assume that it's being fed by that aquifer.

Past Quebec, Little Dry Creek flows through an HOA, requiring a detour up to Arapahoe and down to where the stream emerges from under Arapahoe to continue it's journey into Holly Reservoir. The approach is over a series of weirs (the area is always flood conscious) that parallel the road.

There used to be a pedestrian tunnel that passed under Arapahoe beside the creek, but they closed it off before I moved to the area over three years ago. People must have still tried to use it, because the county then covered the approach ramp with crushed granite.

Holly Reservoir (by Holly Road) is home to a recreational center with tennis courts, a swimming pool, and water slide. The creek meanders it's way through the basin and under the dam. In the case of a massive(!) storm, there could be a lake here. I can't find any record of there ever having been such an event but better safe that sorry.

Holly Dam

Little Dry Creek at the outflow of Holly Dam

Just below Holly Dam, Little Dry Creek and Willow Creek merge. Usually the resulting Creek takes the name of the larger stream, but not in this case. Willow Creek is usually larger, has traveled further, and occasionally will create a lake behind Englewood Dam but the creek that flows from this confluence is called Little Dry Creek.

That's Willow coming in from the left.

In this stretch, Little Dry Creek widens out and cuts a fairly deep gorge. There's also a steepening incline.

The Highline Canal leaves the mountains in Watertown Canyon and flows under the influence of gravity for 66 miles (in the past as much as 71 miles) to the Rocky Mountains Arsenal in northeastern Denver. Along the way, it crosses several natural streams, including Little Dry Creek. It does so by following lines of elevation contour. Natural streams generally cross contours at right angles. The crossings present engineering problems.

There are several places where the canal crosses over streams on water bridges called "aqueducts". The photos above show the syphon where the canal crosses under Little Dry Creek. I would have taken a picture from the top except the canal usually doesn't flow during the winter months.

The canal flows into the tunnel from the left (south) and exits a little lower from the right (north). It works pretty much like syphoning gasoline (or any other fluid) from a tank. The starting level is above the outflow level, so the syphon doesn't have to be primed, which is good since the canal is dry for most of the year.

Little Dry Creek is temporary home to many water fowl. Ducks are common but I've seen many others including egrets and herons. They don't usually make themselves at home but they visit often.

After a brief run down between a meander in the Highland canal, the creek takes off through backyards in Cherry Village, so I had to start some road work down Orchard and Long to University Boulevard where I picked it up again near Quincy. From there, it's an urban aqueduct, flowing between concrete walls.

It feeds some private lakes...

and water features in a golf course.

but most of it looks like this for the rest of it's course.

This is South Denver and Englewood with many shopping areas and apartments so flood control is pretty tight. As many tributaries that have joined the creek, I would not be surprised to see it clear its banks (I've never seen it but I wouldn't be surprised.) It doesn't get water directly from the mountains so the main thing that leads to flooding, melting snow pack, isn't that much of an issue.

Concrete culverts don't really draw me, but there are some points of interest here 

This was a surprise to me. I have seen many of the early sites of gold finds...Clear Creek, Montana City, Bear Creek confluence with the South Platte. These are all streams from the mountains. They erode mineralized, crystalline rock. This first significant gold find was from Little Dry Creek, a creek that runs it's entire course through the debris that has been washed from the Rocky Mountains. That means that a pocket of gold must have collected somewhere by an ancient stream, waiting until Little Dry Creek found it and washed it down to present day Englewood where it waited for William Green Russell to come along from Georgia to pan it out. Why was he even looking here?

Nearby, the creek runs below ground to travel under the Englewood shopping district.

By the time I got to the other side, it was too dark to finish photographing the last section of Little Dry Creek, but a couple of weeks later I made a supply run to the area and finished the tour.

The tunnel in the background is where Little Dry Creek emerges from underground in Cushing Park. Here at the confluence with a drainage stream from the park, it looks like a rushing mountain stream. It's landscapes....the rocks were placed.... there's no telling where they're from. They're there to prevent erosion of the bank.

A little further down the rocks give way to a concrete channel as the creek passes under the railroads and the CanAm Highway (Santa Fe) on its last approach to the river 

The underpass is decorated by a mural by Boulder muralist and graphic artist Amanda Wolf (2021).

An overlook over the South Platte River gives a good view of the confluence.

You have to cross the river by the nearby footbridge to see the mouth of the creek 

There's a low overflow dam just upstream.

At the river, I checked the elevation again and found it to be 5256 feet. That's an elevation loss of 464 feet. I'm glad it was mostly downhill.

So that's the Little Dry Creek from beginning to end. I'll be saying more about its contents. And I'll show you some rocks I encountered along the tour.

Have you ever followed a creek from beginning to end? Do your homework first and stay safe.

Clear Creek Station to Pecos Junction Station

A nice thing about train rides to hikes in Denver is that the stations are often situated to provide good vistas of where you're going.

The snowcap is Mount Blue Sky (formerly Mount Evans). The double peaked mountain in the foreground just to the right of the power pole is Mount Morrison. Red Rocks Park and Amphitheater is at the base of Mount Morrison. The view is from the train as it is pulling into Broadway Station.

 

On this trip, I'm going thataway. The low mountain in the foreground is Green Mountain. It's one of the foothills between the Rockies and the Colorado Piedmont, a pile of the stuff washed out of the Rocky Mountains and the Ancestral Rockies. Behind the Home Depot are the Table Mountains. That's the direction I'm going. No clouds, it should be a clear day for a short hike.

Olde Town Arvada is convenient on this route, so, being the milkshake fanatic that I am, I make a stop on the G Line before each hike to get a snack. In my wandering, I spotted this Catholic church, the Shrine of St. Anne's. The cornerstone was dedicated in 1920, making it a product of the "wild west". 

Saint Anne was the mother of Mary, who was the mother of Jesus.

After Olde Town, I reboarded the train and headed for Clear Creek Station. 

Clear Creek and Clear Creek Trail is just down the hill. 

This leg of the G Line hikes is basically a walk around the perimeter of Martin-Marietta's asphalt plant, a little over two miles. 

I had planned to take a sample of the sand from the Creek bed to look at, but it turned out to be black mud, so I changed my mind.

 The huge piles of asphalt were too near. I have to credit Martin-Marrietta, though, the area didn't stink of asphalt so they must be taking some concern for the environment.

I'm sure you're familiar with asphalt. It's what they pave roads with. Asphalt, or bitumen, is a sticky, semisolid material that is either derived from petroleum (the heavy part left after the oil is refined) or is drawn directly from the ground. Bitumen mixed with clay, the material actually used to pave roads, is also called "asphalt". I don't know where this stuff in these pictures is from but the Pierre shales that surround the Denver Basin contain a lot of petroleum and there are many wells to the north and east.

Another confluence...this is where Little Dry Creek joins Clear Creek. The actual confluence has been altered by an artificial pond. There are several such ponds between Arvada and Denver and they seem to be popular with anglers. I met several on this trip.

This Little Dry Creek isn't the same one that runs through my neighborhood but I have visited it before at the Westminster Station (Friday, June 21, 2019, Terminus: Westminster).

This isn't the horse I rode in on. It's traveling the B Line from Westminster Station to Pecos Junction. I'll hike that one after I finish the G Line.

Again, I have to commend Martin-Marrietta. The installation is very near Little Dry Creek Lake (pictured above) and the lake is popular with anglers and water fowl alike.

Clear Creek is a respectable stream here. I'll be separating from it after this hike because it heads north east away from the G Line, which takes a 90° turn south on it's approach to downtown and Union Station. I'll be following Pecos south to 38th Avenue,then east to Fox Street. That'll get me to Fox Station, and the following hike along Fox Street will take me to the end of the G Line at Union Station.

All of these station-to-station hikes have been above a geologic depression in the Earth's crust called the "Denver Basin". It's a geologic basin instead of a topologic basin because it doesn't show on the surface (or on topological maps). It's far underground buried beneath the Dawson, Arapahoe, and Denver formations.

As the Rocky Mountains began rising up, water was already tearing them down and the erosion products were washing out across the plains. Although it's sorta hard to picture it, over the millions of years between then and now, the rocks of the Earth's crust can bend and flow and squeeze like putty and it did here. As the Colorado Plateau rose, as in counterpoint, the land to the east buckled downward, and as debris piled up, the crust sank under the weight until a great bowl full of dirt, mud, gravel, and boulders formed and then they built Denver right on top. It's a long way down to hard rock...as far as 3900 meters (13000 feet).

If you enlarge the blue diamonds in the pictures above, you can see that Martin-Marrietta is proud of their commendations. NAPA is the National Asphalt Pavement Association and to quote their website the commendation is to "help asphalt mix producers and paving companies improve operations and safety as well as recognize employees and partners for a quality work." So I guess the Pecos Junction plant has something to be proud of.

Again, most of these stations provide good views of the mountains. Up to now, my only exposure to Pecos Junction Station is from the train and the platform is tucked away beneath highway overpasses. It's an important station in that it provides a switching site between the G and B Lines but it's not very scenic being situated in an industrial area 

The parking area is up top with a long, covered pedestrian walkway leading to elevators and stairs down to the platform (always gotta be one last obstacle at the end of a hike!)

The mural on the platform is a piece by Bimmer Torres called "Roots Crossing". It illustrates a primary issue in the area... transportation.

And there I was set to utilitize that very thing and go back home.

I have mixed emotions about industry but I can't readily dismiss it. Our modern world depends on it. What are the industries in your area? How do they fit into your world?