Let the River Run

Start by listening to this song.  Do it.  

In the middle of May Karina and I set off on another semi-planned adventure to ride the length of the Logan River from the headwaters to its confluence with the Bear River.  I hatched this scheme as a way to get to know the watershed we live in and I think it was pretty successful.  

I’m currently a student in the department of Watershed Sciences at USU.  The goal of the department is to “…bring science to the management of watershed ecosystems in Utah and the world.”  For the graduate students, the department works to combine research and courses in aquatic ecology, hydrology, geomorphology and climate sciences into an interdisciplinary program (go ahead and take a look at how that works at http://www.cnr.usu.edu/wats/).  It’s a pretty diverse department with research going on in many different scientific fields, but with a focus on how each discipline functions within a watershed.  For my part, I wanted to see how the things I’ve picked up as a graduate student in the last two years inform my view of a watershed. In addition to that, it was a great reason to break out the bikes and adventure with Karina.  

The Logan River Semi-Planned Adventure - the blue line is our route, the pins indicate stops and what we talked about.  

I’m going to be using the term watershed a whole lot, so I had better provide a definition.  The EPA says “A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place.”  In the case of Logan, where I live, everything upstream flows into the Logan River, so we are part of the Logan River watershed.  The Logan River itself flows into the larger Bear River, so we are also part of the Bear River watershed (and if you ever want to talk about the Bear River with me some day I would love that, it’s one of my favorite rivers). 

My home watersheds

Water is everything; it shapes the landscape and determines where people can live.  Whether in the form of a solid (ice), liquid (water) or gas (water vapor), water is amazing.  The water cycle is another important concept to consider here.  Water changes between three forms regularly as it turns from liquid in rivers, lakes, and reservoirs to vapor through the process of evapo-transpiration, then to rain or snow through precipitation, and finally back to flowing water through discharge. 

The three phases of the water cycle - precipitation (rain or snow), discharge (rivers, lakes and aquifers), and evapotranspiration (clouds over the evaporating Great Salt Lake)

Here in the Intermountain West most of our precipitation comes during the winter time as snow.  This is where we’ll begin our discussion of the water cycle – precipitation.  Precipitation in the form of rain or snow is what fills the lakes and rivers around us.  In the mountains the air stays cold for a longer part of the year than lower areas, so the snow accumulates over the course of several months (this winter there was 8 feet of snow at Beaver Mountain).  The accumulated snow represents most of the water that will be used during the year to supply homes and irrigate crops. 

The beginning of our ride up at Beaver Mountain Ski Resort.  Note the shrinking snow pack, we were just at the beginning of Spring Runoff.  

During the spring the snow begins melting and flowing through the ground and over the ground into the Logan River and its tributaries, making the rivers run much higher than during the rest of the year.  We call this Spring Runoff and it represents the second part of the water cycle – discharge.  Some of the water percolates through the soil and into underground aquifers, but a lot of it makes its way to the rivers.  Rivers are part of larger networks of tributaries that deliver water kind of like an upside-down tree – small streams (like Beaver Creek pictured below) flow into larger streams (like the Logan or Bear Rivers), which also flow into larger streams, eventually collecting enough water to be as large as the Bear River.  At this point it is completely appropriate hum “Give Said the Little Stream.”

Beaver Creek

Lower Logan River

The next part of the water cycle is evaporation and transpiration - evapo-transpiration.  Evaporation happens when heat turns liquid water into vapor.  Our area is really hot during the summer and we don’t get much precipitation during the non-winter part of the year, so rates of evaporation are higher than rates of precipitation – and that’s the definition of a desert.  Transpiration happens when a plant brings water up through its roots and then releases it to the atmosphere as vapor (after making sugar and other plant materials).  Water vapor moved to the atmosphere by evapo-transpiration will eventually condense and come back down as precipitation, starting the water cycle all over again. 

The plant part of the water cycle that is responsible for transpiration, particularly the wetland plant part at the bottom of the watershed, is what I study.  In addition to driving part of the water cycle, plants also provide food for herbivorous animals and they stabilize the banks of rivers with their roots (which in turn also provides habitat for fishes).  Willows and cottonwoods are the primary trees growing along the Logan River.  They’re both pretty and functional, as depicted below. 

Willows are neat, stabilizing the river bank here with its roots and providing shelter for small fishes from the heat and predators.  

Willows are great, adding organic matter to the river as leaves fall off and are decomposed.  

Higher up in elevation trees are continuing to transpire water, but they’re also changing the soils they grow in and the shape of the land beneath.  Some plants, like trees, live for many years or decades but still lose some roots and lots of leaves every year.  This dead plant material is then decomposed by bugs, bacteria and fungi in the soil, which leave behind carbon and nitrogen and other important elements that make the soil richer and able to support more plants. Some hardier plants, like my personal favorite – mountain mahogany – can actually start making their own soil as they decompose rocks they’re growing on.  Trees are the coolest. 

Every fall aspens drop leaves onto the soil that are quickly decomposed by soil microbes, leaving little evidence of litter behind once the snow melts.  

Pine trees drop needles that are full of tannins, a compound that makes them resistant to decay, so there are deep layers of litter (or duff) below pine trees.  

Being with the snow, aspens and pine trees has clearly overwhelmed Karina.  I get it.  

Then we recovered and celebrated the beauty of the world we live in.  

Trees can also shape the larger landscape.  The extensive root systems of some plants can hold the soil together and prevent landslides.  In some places the roots systems of plants hold sediment back as water moves through, slowly filling in river channels and ponds with mud and debris (like the way beaver dams change rivers into wetlands into uplands).  And sometimes these plants are just fuel for fires, and once they are burned the area will be prone to landslides and lose all of its sediments to other places.  Plants are the coolest. 

The road to Tony Grove

See how the vegetation higher up on the mountain is different than the lower elevations?

See how the slope is different in the areas with pine trees and the ares with aspen and sage brush?
See how fast we were riding?

Geomorphology is the study of landforms and the processes that shape them, and it is often focused on rivers because they shape and are shaped by the landscape.  One of the best parts of our ride was to see how the shape and power of the river changed based on the slope of the land and how confined the river is.  If you look at the sediment on the bottom of the river you can get an idea of how powerful the river is at that location because those rocks or that mud were likely deposited there during a runoff event and anything smaller continued to be carried downstream.  Up in the top part of the river where the slope is pretty steep but the channel isn't confined much by the canyon walls the bottom of the river is made up of cobbles that are a few inches long.  The water is moving pretty fast but some of that energy dissipates as the river spreads out. 

Middle Logan River

As the river drops into Logan Canyon the cliffs and Highway 89 constrain how far the river can move and the gradient is still quite steep, so the bed of the river is composed of boulders than can be more than a foot wide.  All the energy in the water is responsible for shaping the landscape that continues to shape the river, the Logan River itself is responsible the formation of the canyon in the first place.  As the river flows over and through the canyon it carries away rocks and dirt (erosion), deepening the canyon as it goes, this has been happening for thousands of years.  Through the slow process of erosion and tectonic forces bending and folding the Great Basin, a deep canyon was eventually formed and continues to change. 

Curvy part of the canyon with lots of blind curves

Seriously powerful part of the river, as manifested by the loud and fast flow and the giant boulders in the water.  

Even where it could carry you away, it's peaceful to sit next to water, especially compared to furious pedaling around blind curves.  

In addition to driving the river, the extra gravity helped our bike ride go pretty smoothly, we hardly had to pedal at all until we decided to take a quick ride as far up the road to Tony Grove as we could.  Even in the middle of May there is so much snow in the mountains the road to the top is closed until summer time, so we had it all to ourselves.  We explored the trees and enjoyed the snow.  And then rode down the steep road completely disregarding the speed limit – we got going 40 mph at one point!

Pretty happy to be riding bikes and checking out the Logan River

Going so fast

Such a fun road!

In the lowest parts of the river, free of the canyon, the river meanders in large oxbows and the bed of the river is composed mainly of silt and sand because the river is flowing slow enough that these small sediments fall out of the water column.  Here in these flat lands is where wetlands form most often as water slows in ponds, sloughs and lakes.

Cutler Marsh and Reservoir with the Bear River Range in the background, the Logan River is coming in from the right side of the image.  

Sometimes rivers are slowed and impounded by man-made dams that create reservoirs.  This is definitely the case in Logan Canyon where three dams are located within 4 miles of the mouth of the canyon.  Dams are built for a number of reasons, including flood control, irrigation, and generation of hydropower.  The dams on the Logan River provide all three of these benefits, they can capture water when the river is running high before it reaches the lowest parts of the river where houses are located, two of the dams back up water to the inlets of canals that distribute water throughout the eastern side of Cache Valley, and they were originally built by Utah Power and Light to generate power for Logan City.  Because Mother Nature usually wins despite our best efforts, the dams on the Logan River are slowly losing their capacity and functionality because they’re filling up with silt, the result of slowing down silt-laden rivers enough for all the sediments to fall out. 

3rd Dam in May 2014 spilling a lot of water.  Now (August) it's hardly letting any water out.  

It’s pretty easy to find your way down the Logan River, as Highway 89 runs alongside it.  But sometimes the flow of water is not so clear, as is the case with Rick’s Spring.  Turns outs Rick’s Spring is not actually a spring, it’s a fault in the hill side where water that has seeped into the soil uphill comes seeping out (rather than from coming from an underground aquifer, which is the case for a spring).  This fun fact wasn't discovered until the 1950’s, when hydrologists noticed the ‘spring’ followed the same patterns of high and low water as the Logan River (plus a lot of people who drank the water from the spring got sick from Giardia, which doesn't happen if the water comes from an aquifer). 

Rick's Spring.  If you ever pull over for a visit, look inside to see the crack in the rock at the fault line.  

Water flowing away from Rick's Spring.  And hand-to-big-toe pose to illustrate the tricky balance water managers on the Logan River face, as they almost always have too much water or not enough water, depending on the state of the winter snowpack.  

There are several places along the Logan River where water comes up from the ground like at Rick’s Spring, this is due to the geology of the mountains – they’re composed primarily of sedimentary rock called limestone, which is more easily dissolved by weakly acidic water (which includes rain) than other rocks.  Limestone is composed mainly of different forms of calcium carbonate, the same stuff snail shells and corals are made from, and many limestone formations are actually layer upon layer of animal shells.  The world’s largest cave systems are found in limestone because it can be eroded by groundwater and there are a few cave systems near the Logan River.  On the surface, water in the form of precipitation and river discharge eroding the limestone has made for a plethora of climbing opportunities in Logan Canyon that are one of the highlights of living in Logan.  Calcium carbonates from the rocks are also responsible for the awesome turquoise color of Bear Lake. 

Limestone at China Cave, which isn't actually a cave but an overhanging rock wall carved by the Logan River.  Note the cool texture of the rock created by dripping water.  It's also a nice place to have lunch.  

After 30 miles of pretty easy downhill riding (alternating between taking our time cruising downhill and pedaling furiously around blind curves) we made our way into Cache Valley.  Due to some road work at the mouth of the canyon, our entry into the valley required a heart breaking pedal uphill toward the University.  However, once we got out of the canyon, we got to see where the river was doing most of its modern day work.  Logan Canyon and the benches of Cache Valley were carved over thousands of years through the erosional power of the Logan River and Lake Bonneville.  In modern times the sediments left over from Lake Bonneville have created some pretty fertile soils that can still only produce crops with the addition of water from the Logan River.  As I mentioned before, Utah is a desert, so crops can only grow with the help of irrigation.  Before white settlers came into the valley, living off the landscape required sticking close to the rivers, where water is usually available year round, or travelling from place to place to find food.  In order to support a permanent agricultural population, white settlers dug a series of ditches to take water from the rivers (starting with the Logan River) and deliver it to their fields to grow grains, alfalfa and vegetables.  Through this system of canals and the reservoirs I talked about earlier, farmers are able to stretch out their use of Logan River water throughout the year, rather than during Spring Runoff alone.  Irrigation is a pretty huge undertaking that requires a lot of cooperation.  In an interesting bit of history, early Mormon settler’s were sometimes called the Lord’s Beavers because the communal nature of the church structure enabled members to build really large diversion works together that weren't possible for individual families. 

North Logan-Hyde Park-Smithfield Canal, which gets its water just above 2nd Dam and diverts it along the eastern side of the Valley

Alfalfa on the Logan Bench irrigated by Logan River water

Different types of irrigated crops in the Cache Valley

We ended our ride at Cutler Reservoir, where the Logan River meets the Bear River before flowing on to Box Elder County.  Cutler Marsh is the lowest point in Cache Valley (but we had to ride uphill to get there because of a glitch in my semi-finished plan), there are extensive wetlands because it’s very flat and very wet.  Thousands of White-faced ibis stay here every year, supported by the bugs in the wetlands and in the nearby irrigated fields.  From this vantage point we could see the tops of the Bear River Mountains 5,000 feet above us, still covered in snow that would eventually make its way to this reservoir or the fields we had just passed through.  We also saw the beautiful Wellsville Mountains, so steep because there are no perennial rivers like the Logan to erode them. 

Finishing victoriously at Cutler Reservoir.  Sometime I'll have to tell you about our adventures in and around the Wellsville Mountains, which you can see in the background.  

My conclusions at the end of the journey were similar to John Wesley Powell’s words about watersheds – 

"[Watersheds,] that area of land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community."

Water connects all its users and I think it also connects scientists beyond the artificial disciplinary boundaries we surround ourselves in.  It’s impossible for me to look too closely at one spot in the river without my mind wandering to where that water is going and who else will be using it.