Category Archive for ‘water’ at Beside the Stream

Archive for the 'water' Category

Rafting season

Published on June 10, 2008 in water. 0 Comments

This is a parade of five rafts heading towards the rapids. A friend who runs a raft company says that it’s been a very slow season. She thinks the RVers who usually raft with them didn’t come this year because of high gas prices. This healthy flotilla of paying guests was a flash from the past.

We may have passed high water this year.

The red line is this year’s hydrograph, and you’d think those high flow days would come as a surprise, but they don’t. For two days this year the river flow doubled… and I got kayaking pictures from both days. Those peak flows are ecstatic. A lot of the reshaping of a river occurs in those few days when the flow is two and three times higher than the mean.

High water is a thrill but I don’t mind the lower flows of summer. My personal favorite is tubing season, but for that you have to wait until July, when the flow is below 600 cubic feet per second. Drinks and snacks are optional.

High water 2

Published on June 3, 2008 in water. 2 Comments

The last time I took high water photos was 5/21 when the river was running 6,400 cubic feet per second–it’s the red spike on the hydrograph. We had a freeze and the melt slowed, and then we had a hot wind and the melt increased. Monday the river was at another high–people estimated it was 5,800 cfs.

Kayakers have gotten more practice and are ready to try the big waves. At Smelter Rapids there are about 20 people watching; there is a group of kayakers getting into their dry suits in the parking lot; and there are three kayakers taking turns on a six foot standing wave.

This is the same guy who kayaked alone here last high water. His kayak is facing upstream, and he is being held in place by the backwash created by a big boulder in the river. He has big water flowing downstream, the foaming rush pushing upstream, and he’s balancing in the fulcrum of these forces.

He makes it look easy but it’s not.

It’s pretty hard to settle into the sweet spot when the forces are so enormous.

Dang hard.

I heard that Fire and Rescue is averaging 3 saves a day from here, because there’s a tight eddy on the other side of the river that people can’t get out of, and the water is icy. Of course, it’s not the kayakers who need rescuing.

It’s the rafters who get thrown in the rapids and can’t get to the other side of the river. I’m all in favor of scantily clad rafters in summer, but not in spring. This water is from snowmelt, and it’s fierce.

When it comes to cold water safety, it’s all about the clothes.

Trees swept downstream

Published on May 30, 2008 in riparian edge and water. 2 Comments

We think of streams and rivers as fixed features of the landscape, but they’re not. Trees continually fall into the water because the banks are always moving laterally (unless the streambed is artificially restrained by riprap or levees). A river is constantly shifting because of the way water flows.

Water that flows in a river moves like a corkscrew, twisting in on itself. Water flowing at the bottom of the river is slower because of the friction between the water and the riverbed, while the water on top flows faster. When a river bends, the faster water on the surface pushes against the outer banks and dumps trees into the waterways, while the slower siltier water at the bottom slips to the inner bank and drops some of its sand or gravel.

Most of the waterways we see are controlled by dams, where the high flows are moderated and the trunks are removed from the river. Here we have a natural stream in the spring, sweeping great trees downstream.

This is near the start of our walk, with tree trunks piled at the point of this little instream island.

Next we have this log caught midstream a wee bit upriver.

Big logs collect smaller logs and branches,

and you can see that the water was much higher a few days ago, when the flow around the near side of this tree caught a bole and a lot of small branches.

By midsummer, this torrent of snowmelt will have faded to a babbling brook. This huge trunk will be immovable… until next spring shifts it downstream again. By nature, a stream is a messy, trunk-littered path.

High water

Published on May 22, 2008 in Small town life and water. 2 Comments

The Animas flooded its banks today,

and with the high water I went to Smelter Rapids, the town’s best white water.

It was big water today, one of the highest flow days of the year. There was one kayaker out there, and maybe twenty people watching.

Can you see the joy?

The balancing of immense forces? This guy is likely Olympic caliber–there are a lot of world champion and Olympic kayakers living here

and I assumed everyone was there to watch his perfect form. Instead,

the main attraction was a group of four commercial rafts due at 2:15. Two rafts made it through intact, one raft lost and recovered a passenger, one raft flipped…

and it was really entertaining.

An Act of God (Time: one month)

Published on May 7, 2008 in time and water. 2 Comments

In early April, this debris flow was liquid and the wall of the irrigation ditch was cut to allow the material to keep moving downhill.

A month later, the ditch wall is finally repaired, the ditch is filling, and there’s a plan. I got the scoop from an engineer who worked for the ditch company, which had come to an agreement with the landowner, the county and the Army Corps of Engineers.

This is the problem: a big chunk of the cliffs at the top of this mountain crashed down in 2001, leaving a huge pile of pulverized limestone hanging 1,000 feet above the road. It’s that upside-down triangle at the top of the mountain. This spring, millions of gallons of limestone and water slurry moved downhill, and the rest of the pile is expected to come down over the next ten years. There are four loose boulders up there that are as big as houses, and that is a problem. But they have a solution for the pile of pulverized limestone.

The ditch is going to be put in a culvert at this point, and wing dams will be built to funnel the slurry over the ditch and down through this orchard to the river. There’s no way to stop it and no way to move it, so the plan is to let it flow.

The pulverized limestone has dried to the consistency of cement, and both rows of apple trees will be dead before long. This debris flow is considered to be an Act of God, so the ditch company pays for the ditch work, the road department pays for keeping the road clear, and the landowner has to pay for the construction of a slurry channel through his land. I wasn’t clear on who pays for the wing dams, but it might be the Corps.

According to Wikipedia, ”an Act of God or act of nature is a legal term for events outside of human control, such as sudden floods or other natural disasters, for which no one can be held responsible.” (attributed to Black’s Law Dictionary).

This debris flow is classified as an Act of God, but it sure looks like an Act of Gravity to me (no higher power required). If God was involved, perhaps it was that the limestone and water slurry was so liquid. If it had been thicker, said the engineer, it would have swept all the trees along with it, and then you woulda seen a mess.

Prairie Dogs and Water

Published on May 2, 2008 in water. 11 Comments

Around here, people think prairie dogs are terrible pests. Ranchers say: if we called them prairie rats instead of prairie dogs, city people wouldn’t think they were so cute. Which seems like a silly thing to say, because prairie dogs are objectively very cute and don’t have naked tails.

If the people who’d like to remove prairie dogs from the landscape could only see underground, they’d feel differently. If ranchers had x-ray vision, they’d love prairie dogs, because prairie dogs change the pathways water takes through the land. (RDennis, this post’s for you.)

When rain falls on grasslands, most of the water that falls moves back into the air through evaporation. Rain that falls on vegetation will likely evaporate. Some of the water runs overground as run-off, which will possibly join a stream or more likely evaporate. Of the water that soaks into the soil, nearly all of it is taken up by the root systems of grasses and transpired back into the air. As a rule, rain that falls on the grasslands does not soak down to the groundwater, where it could replenish local springs and streams. Unless it falls on a prairie dog town.

The soils in prairie dog towns are moister than the soils in the surrounding grasslands, and higher in organic matter. This may account for the increased populations of tunneling insects and worms that honeycomb the soil profile in a prairie dog town. Macropores are tunnels with a diameter greater than 1 millimeter, and they promote the rapid transport of water through the soil. The macropores in a prairie dog town allow rainfall that would have been lost to evaporation or run-off to trickle down to the groundwater and replenish the local vegetation.

Flury, M., and H. Flühler. 1995. Tracer characteristics of brilliant blue FCF. Soil Science Society of America Journal. 59:22-27.

Here we have a photo (properly attributed, no less) that shows grasslands soil where dyed water was poured on the surface, and then the cross section was excavated. We can see that there’s no zone of saturation moving down from the surface, like we were taught in Hydrology. Instead, the water runs down holes build by animals, worms and beetles, and through channels left by decayed roots.

By allowing prairie dogs to tunnel the grasslands, you change the pathways water takes through the land. Instead of rain disappearing through evaporation, transpiration and run-off, it settles deeply into the land where it can do some good.

If ranchers had x-ray vision, we’d see less of this

and more of this

(Prairie Dog Rapture by Anthony Falbo)

Crossing the river

Published on April 20, 2008 in Colorado women, dogs and water. 4 Comments

My friends decided to build a bridge because

a cottonwood fell across the river right in front of their house. It was close enough to where they wanted to cross that it seemed like a reasonable idea.

This is the view from upriver, looking downstream. Of course, it wasn’t this perfect by accident. The tree trunk was moved to the best place and is being stabilized before a handrail gets attached. Christy and Steve moved the cottonwood trunk into place with a comealong. (This comealong sells for $12.09, so it’s definitely the cheapest way to move big weights.

This is the view from downstream, looking up. The structure holding the near end of the trunk is artfully obscured by the red twig dogwood.

This end of the tree is forked, and they built a structure of notched logs to support it.

This is the only homemade bridge I can recall seeing. Most every bridge we cross has state sanction… but not this. I saw Christy scamper across it, but I’m holding out for a handrail until the water is warmer

and the dog wanted me to mention that she has no intention of ever using the bridge. Ever.

Mudslide!

Published on April 7, 2008 in water. 2 Comments

The road on the other side of the valley was closed by a mudslide. The mud was four feet deep across the road, and it took two days to get the road cleared.

This is where the mud entered the road.

A major irrigation ditch runs parallel to the road. It’s not filled with water yet, so mud filled the ditch and flowed in both directions. The road crew cut a hole in the ditch so the mud could flow down into the orchard and out of the road.

That red triangle of earth is a cross section of the far wall of the ditch–the near wall is under mud so you can’t see it. The road crew cut a notch in this hundred year old irrigation ditch so the mud could drain from the road and hopefully from the irrigation ditch as well. Below, a section of the rail fence was removed so the mud wouldn’t sweep it away. There is a lot of mud being held in by the solid fence on the left.

I realized the next day that I didn’t have a shot of the rockslide where this material originated. Today was overcast so the picture is a little bland, but you can see how the color of the mudslide matches the color of this high altitude rockslide.

This is technically a debris flow, not a mudslide–it’s not topsoil that’s moving, but subsoil. In the San Juan mountains, these debris flows are triggered by water; this one in particular is from last winter’s heavy snowpack and the quick meltdown. In some places, mudslides are a product of human interventions like deforestation, agriculture or road construction; here they’re a function of the region’s geology, and of water.

The debris flows start when the snowpack melts, and continue intermittently through the summer. A big rainstorm can move the mountains as well as the melting snow. In this area, water moves the earth.

Water Quality - color

Published on February 26, 2008 in water. 0 Comments

Algae is blooming at the head of the valley.

The water is almost fluorescent green right where the rapid mountain stream slows down to fill a series of deep pools surrounded by cliffs. The river is from a forested watershed, but I’d guess a bunch of nutrients washed into the water somewhere upstream. Fertilizer from the golf course? Wastewater? The cliffs hold warmth from the sun, increasing water temperature and allowing the phytoplankton to go wild on those extra nutrients. Above we have the water entering the canyon, here’s the water in the pools

and here is the water as it enters the valley floor:

Twenty miles downstream the same day, the water is clean. The excess nutrients grew phytoplankton that was eaten by fish and insects and other living things. What a world we live in.

Ditch Water 2

Published on February 21, 2008 in water. 0 Comments

Our irrigation ditch is typical of the water distribution system in this region. Here’s the ditch today, very low:

You can see that the ditch is unlined. There are stones in the walls to reduce erosion, and the bottom is earth. It’s really no more than a trough dug in the earth that the river is diverted into. It looks like a casual system until you see the water gate across the road.

This picture is from November, and you can see that the ditchwater is being diverted towards us where it joins the stream that flows into the river it came from–this water just became return flow at this point. During the growing season, the gate is usually open. From here, the water would flow through a siphon under the stream and continue for miles and miles in ditches down the valley.

There is another big ditch that runs miles and miles along the other side of the valley. This ditch is empty during the winter… and it’s another honking big water diversion.

Can you imagine how much water is soaking down into the ground from these ditches??

You’re right; it’s a lot. So much water soaks into the ground from these giant ditches on both sides of the valley (and from the channels that feed off these ditches) that the wells in the valley are actually fed by ditchwater seeping down to the groundwater. The ditch systems are over a century old, and haven’t been updated since then except for the gates. Lining the ditches would save huge amounts of water, but the valley wells would run dry. This little local conundrum is repeated in valleys across the arid west.

Beside the Stream