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.
