riverproject.html

Project Evaluation Report

Sarah Stevens

Summer 2004

Public Education & Business Coalition

Fund for Teachers Grant Program

INITIAL PROPOSAL:

I. Project / Activity Description:

This summer I hope to complete an activity that involves charting the changing water quality of the Colorado River as it makes its journey through the west. This activity will expand on a current program already implemented with my classes. This current program is called the “Rivers of Colorado Water Watch Network” or "River Watch". The Colorado Division of Wildlife (CDOW) developed this program that involves volunteers in protecting the quality of Colorado Rivers. The program links environmental protection with education in a meaningful, hands-on project for Colorado residents.

Participants currently are made up of middle and high school students, their teachers, watershed management groups and stakeholders. The program began in 1990 with 19 schools along the Arkansas, Eagle and Yampa rivers. Annually, 140 groups are monitoring all eight major watersheds in Colorado. River Watch is sponsored by CDOW and administrated through a non-profit organization entitled Colorado Watershed Network (CWN). CWN provides staff to train volunteers, analyze samples and provide administrative expertise.

Data collected is used by federal, state and local agencies to make decisions about river/water management. The Colorado Department of Health has already used data collected from Clear Creek in hearings to determine water-quality standards for the stream. Currently, my eighth graders have been involved in monthly water quality measurements on North Fork Clear Creek.

I would like to expand my current program to include water quality analysis on the Colorado River system. I would utilize my summer experience with “Fund for Teachers” as a case study example before my new eighth grade students embark on their own analysis of the water quality on North Fork Clear Creek. Because of the importance of the Colorado River and its trek to its destination, I feel my proposed activity will benefit my students as both a case study on a major river system and a lesson on resource management.

My proposed activity would follow the Colorado River from its headwaters in the Never Summer Range, Colorado, to its final destination in Mexico. Along the way I will take water quality measurements and note the local influences on the changes in water quality. The water quality measurement points will be determined by looking at the changing influences on the river and access to the river. After gathering all the data I will analyze the information and determine the causes behind the changing water quality. Some influences that may affect water quality could be the local climate, local geology, human and other animal influences, groundwater, and other drainages.

II. Benefits to the teacher:

This activity will intensify my knowledge on a local river system which has a huge impact on the state of Colorado as well as all the other 18 states and countries that are utilizing the river’s resources. Studying the factors that influence the quality of the river as it flows along its journey will help in the analysis of our local drainage system, the North Fork Clear Creek. From this activity, I plan to create a report that can be used to demonstrate how one can look at water quality data from a drainage system and determine probable influences on the changing data. This journey will also bring to life a river system that many individuals rely on in the present and future. Lastly, my academic background in hydrogeology will be reenergized through this trek from the beginning to the end of one of our most important drainages in the west.

III. Benefits to the students:

Students will benefit from this project in many ways. First off, students will learn about an important Colorado river that carries 87% of this state’s water to the west. In times of increasing water usage, the importance of our planet’s fresh water needs to be recognized and understood. By learning about a drainage system that has an enormous influence on the western states and Mexico, students can begin to understand the importance of their own local systems.

In addition students will benefit in the following areas:

Students will have the benefit of understanding not only how to collect and compile relevant data, but the process by which this data can be presented to the professional community.
Participating students will understand the relevance of science to their environment, how to collect data according to specific requirements and the importance of reporting data to the global community.

· Being out in the field taking water quality measurements will increase student interest through the use of technology. It has been shown that any use of new technology is of benefit to the "at-risk" students, particularly because the challenge of using technology will help keep their interest, as well as prepare them for a workforce that expects them to have these skills.

· Understand more clearly the "big picture" that science paints, rather than just small bits and pieces that traditional textbook activities have taught them. This is enhanced by students being able to collect and share this data with the scientific community.

· Gain a greater respect for their environment as well as understand the direct relevance of science and math to future careers. They will also gain a greater awareness and relevance of science and develop important skills that can benefit them and their future careers.

CHANGES IN INITIAL PROPOSAL:

Since Gilpin County School did not renew my contract into tenure (a common practice at the school), I will be teaching at the Rocky Mountain school for the 2004-2005 school year. I will still be teaching eighth grade as well as kindergarten through seventh. I plan to continue the River Watch project and the watershed analysis with the eighth graders. There will be a new River Watch site assigned near the Boulder Reservoir so measurements on the North Fork Clear Creek will not be continued.

PROJECT SUMMARY:

My project was broken up into three parts. The first part was the Upper Colorado Basin Tour with the Colorado Foundation for Water Education (6/23 to 6/25). The second part consisted of water quality measurements from the Utah/Colorado border into Mexico (6/28 – 7/15). The third part consisted of water quality measurements from the Utah/Colorado border to the headwaters in Colorado’s Never Summer Range (7/27-8/2). All three sections covered 28 days on the road. Compiling and analyzing the data was completed at home in August.

Part One

The first part of the project was with the Upper Colorado Basin Tour organized by the Colorado Foundation for Water Education. Topics covered were as follows:

June 23: Urban Water Use

Dillon Reservoir - Denver Water system
Upper Colorado River Project
Grand County water quality issues
Farr Pump Plant (Colorado - Big Thompson Project)
Northern Colorado Water Conservancy District
Grand County riparian issues
Green Mountain Reservoir (Colorado - Big Thompson Project)
Role of the U.S. Bureau of Reclamation

June 24: Recreational Water Use

Instream flow programs
NRCS Snotel sites
Clinton Reservoir
Summit County operations for water uses
Snowmaking
Vail Kayak Park
Recreational in-channel diversions
Eagle River cleanup efforts
Wolcott Reservoir
Colorado River Water Conservation District
Rafting trip on Colorado River (Glenwood Canyon)

June 25: Agricultural Water Use

Tamarisk and noxious weeds
Colorado State Conservation Board programs
U.S. Fish & Wildlife endangered fish recovery programs
Cross Orchards Historical Farm
History of irrigation in the Grand Valley
Salinity demonstration
Colorado River model
Grand Valley irrigation issues
CSU Agricultural Experiment Station
Turf grass and landscape technologies
Irrigation technologies
Selenium issues in the Grand Valley and Gunnison Basin

The group at Clinton Reservoir (I am up front kneeling in the red jacket)

Blue River near Green Mountain Reservoir

Green Mountain Dam

Low water levels in Green Mountain Reservoir

By attending this tour I got an understanding of all the management and planning behind municipal, industrial, recreational, environmental, and agricultural demands. The tour also provided background information on all the different groups of individuals involved in the management and planning of our nation’s waters. I also met so many individuals that have my similar passion for our Earth’s water but with their own varied views and interests. Had I not been a scientist before teaching, however, this crowd would have been rather intimidating. Summarized below are the big points I pulled from this tour.

The Colorado River gets its name from Father Francisco Garces, in 1540, because of its red mud.

The Colorado River travels 1,360 miles in the United States, making it the U.S.’s fifth longest river. It drains 245,000 square miles, brings life to 27 million people, and irrigates four million acres on seven states and two countries. It is said that every molecule of water in the Colorado River Basin is used three times before it reaches the Pacific Ocean. Nearly two thirds of the annual water flow in streams and rivers occurs during late spring and early summer runoff. Only three percent occurs during winter months. The greatest demand for water occurs during the summer months when flows are low. Riparian habitat makes up less than three percent of the land in Colorado, but is used by over 90% of the wildlife in the state. Over 3.5 million people in the cities and farms east of the Continental Divide rely on water from trans-mountain diversions (through tunnel drilled through the mountains). Denver gets 55% of its water from the Colorado River. Twenty five percent of the water used by the state of Colorado from the Colorado River is diverted to the Front Range from the Colorado River Basin through these trans-mountain diversions. Currently, Colorado does not use its 700,000 to 1,000,000 acre feet entitlement annually to the Colorado River.

Because water doesn’t necessarily fall where it is needed the most, it has been stored in reservoirs and then diverted via pipelines, tunnels, canals, and trucks. Water uses are regulated by a complex array of reservoirs, water right laws, treaties, and compacts. Individuals with the earliest water rights get first privileges to the available water (doctrine of prior appropriation). This does not create a problem during years of plentiful water. However, years like the past four years, including this year, have provided less water in Colorado through precipitation and many of the reservoirs are low in storage. More recent water right holders are in danger of not receiving their allocated amounts since there will not be enough water to fulfill all of the water rights. When the Shoshone Power Plant does not get its allocated amount of water for hydroelectricity (with an early 1902 water right for 1,250 cubic feet per second at all times) they make what’s called the “Shoshone call”. The “Shoshone call” is made when there is not enough water in the river to meet their water right. Upstream diverters with junior priority dates, such as Denver’s Colorado – Big Thompson Project, must reduce, replace, or shut off diversions until the Shoshone demand is satisfied.

The Colorado – Big Thompson Project (C-BT) is Colorado’s largest trans-mountain diversion project. This complex system consists of 12 reservoirs, 35 miles of tunnels, 95 miles of canals, and 700 miles of transmission lines. It spans 150 miles east to west and 65 miles north to south. Built from 1938 to 1957, this included the drilling of the Alva B. Adams Tunnel which began from both sides of the divide at the same time, working towards each other. Without the aid of lasers, the two tunnels joined in the middle within hands reach of each other (amazing to me!). At 13.1 miles, this tunnel is the nation’s longest tunnel built for irrigation. What this system does is collects and delivers up to 310,000 acre feet of water annually from the upper Colorado River basin to the Front Range. [One acre foot is about 326,000 gallons of water, or the average amount two urban families’ use annually.] It transports this water beneath the Continental Divide, to the Front Range. This water is first used to generate electricity and is then stored in the Horsetooth Reservoir, Carter Lake (reservoir), and Boulder Reservoir for other uses.

The main water quality issues with the Colorado River system involve selenium, salinity, and turbidity. Selenium is an essential trace element that occurs naturally in the environment. It can be found in rocks, soils, water, and living organisms. The Mancos Shale formation in western Colorado, a marine sedimentary rock, is rich in selenium. This mineral is beneficial to living organisms in trace amounts above .04 ppm but becomes toxic at intake levels above 4 ppm. Selenium levels in water between 2-5 ppm can be bioconcentrated in aquatic food chains and cause reproductive failure, deformities, and other adverse impacts to living organisms. This is especially troubling with the endangered and threatened fish species. High selenium levels affect the Gunnison River Basin which joins the Colorado River at Grand Junction. (My portable water lab did not have the means to measure selenium levels nor was I able to catch and study its affects on fish.)

The level of salinity in the Colorado River is also a major concern in both the United States and Mexico. Salinity affects agricultural, municipal, and industrial water users. High salinity levels make it difficult to grow winter vegetables and popular fruits. Salt in water systems plugs and destroys municipal and household pipes and fixtures. Studies show that salinity damages in the United States' portion of the Colorado River Basin range between $500 million and $750 million per year and could exceed $1.5 billion per year if future increases are not controlled. Damages in the Republic of Mexico have not been quantified, but may be expected to exceed $100 million per year. Salinity (salt) loading of the Colorado River occurs from agricultural and other sources. The Colorado River Basin Salinity Control Act of 1974 allowed the planning and construction of salinity-control projects which have successfully reduced the levels of these unwanted dissolved solids in many locations. However, levels are still above the desirable level in certain areas of the Colorado River where irrigation runoff dominates inflow to the river. I was able to measure salinity and total dissolved solids during my second and third portions of this project and the results can be found in the sections below relating to those trips.

Turbidity levels in the Colorado River arise from an overload of sediment being transported into the river through natural precipitation and irrigation runoff. Visibility levels are reduced and the ability for organisms to carry out respiration and photosynthesis are hampered. I was able to measure turbidity during my second and third portions of this project and the results can be found in the sections below relating to those trips.

The last issue that spiked my interest on the tour was the problem of noxious plant species and their impact on the river system. A noxious weed is a weed that is invasive and alien to the surrounding ecosystem and it is on a federal, state, or local list that recommends or mandates management of the plant. The tamarisk plant is a deciduous shrub/small tree from Eurasia which has displaced native vegetation in or near the riparian zones on over 1.5 million acres of land in the West. Tamarisk is a tenacious plant that has a deep root system that can reach down to 100 feet, its leaf litter deposits salt residue on the soil and it quickly resprouts after a fire. It is able to quickly replace cottonwoods, willows, and other native riparian floodplain species. Along with crowding out streams and rivers, providing poor habitat for livestock, wild animals and birds, increasing fire hazards, and limiting human access to the waterways, the tamarisk plant “steals water”. It uses more water than the native plants it displaces. The West is probably losing between 2 to 4.5 million acre feet of water per year over what native plants would use. This is enough water to supply upwards of 20 million people or to irrigate over 1,000,000 acres of land. Another invasive plant that cohabitates with the tamarisk is the Russian olive. So here we have other competing water users, ones without water rights.

Part Two and Three

The second and third parts of the study involved following the Colorado River from its headwaters in the Never Summer Range, Colorado, to its final destination in Mexico. Along the way I took water quality measurements and noted possible local influences on the changes in water quality. The water quality measurement points were determined by looking at the changing influences on the river and access to the river.

Twenty eight stations were visited and water was sampled and measured for the following parameters; nitrates, phosphorus, turbidity, dissolved oxygen, salinity, temperature, total dissolved solids, conductivity, and pH. These parameters were chosen because they are most similar to the current parameters I test for River Watch. Living organisms in and around rivers depend on the suitability of these parameters at various levels.

I will first discuss the different stations individually and then I will discuss the changes in the individual water quality parameters as I moved from one station to another in a downstream order. One thing to note is I lost all my pictures from part two of my trip due to a failure in the digital camera’s micro drive storage media. A tragedy since pictures say a thousand words.

A summary of the stations are as follows:

1 – Lulu City in Rocky Mountain National Park, Colorado

2 – Below Lulu City at the start of the trail to Lulu City, Colorado

3 – Lake Granby at the Stillwater campground, Colorado

4 – Below Hot Sulfur Springs, above Williams Fork Reservoir, Colorado

5 – State Bridge, Colorado

6 – Dotsero before Eagle River inflow, Colorado

7 – Blair Ranch Rest Area, Colorado

8 – Shoshone Power Plant below outlet, Colorado

9 – Glenwood Springs Delivery Road – below Roaring Fork inflow, Colorado

10 – Highway 340 near Fruita, Colorado

11 – Big Bend, Utah

12 – Upper Lake Powell at Farley Canyon, recreational road 630 off highway 95, Utah

13 – Lower Lake Powell, above dam and marina on north side, Utah

14 – Below Glen Canyon Dam at Lee’s Ferry day use area, Utah

15 – South cove, Arizona

16 – Temple Bar, Arizona

17 – Boulder Beach above Hoover Dam, Arizona

18 – Willow Beach below Hoover Dam, Arizona

19 – Right above Davis Dam, Arizona

20 – Below Davis Dam, Bullhead Community Park beach area, Arizona

21 – Below Havasu Wildlife Refuge, Topock Marsh outflow, Arizona

22 – Cattail Cove, Arizona

23 – Below Parker Dam (Lake Havasu), Arizona

24 – South of Ehrenberg, Arizona

25 – Picacho State Park, California

26 – Below Yuma, before Mexico, Arizona

27 – Mexico canal near old Colorado River channel bed, Mexico

28 – San Felipe area, ocean water, Mexico

Station #1 – Lulu City in Rocky Mountain National Park, Colorado

Near the beginnings of the Colorado River stand the remains of an old mining ghost town named Lulu City in the Rocky Mountain National Park. This is an area of glacial debris, metamorphic, and volcanic rocks. The river flows quietly here, fed by precipitation, springs, and melting snow.

Colorado River at Lulu City

View of the headwaters, Colorado River, with average precipitation greater than 50 inches a year

Station #2 – Below Lulu City at the start of the trail to Lulu City, Colorado

This site is towards the beginning of the 7 mile round-trip hike to Lulu City.

Looking downstream from #2 site

Probe measurements

Station #3 – Lake Granby at the Stillwater campground, Colorado

Bottle used to collect water samples for lab measurements with portable kit

Probe, GPS, sampling bottle, and lab book

Station #4 – Below Hot Sulfur Springs, above Williams Fork Reservoir, Colorado (at the Hot Sulfur Springs State Wildlife Area)

Measurement site #4

Station #5 – State Bridge, Colorado

This is the site of a wagon bridge funded by the State of Colorado in 1889. A newer bridge has since been constructed; however the old bridge still remains.

Measurement site next to raft across river Closer look with GPS unit on rock

Station #6 – Dotsero before Eagle River inflow, Colorado

The Eagle River joins the Colorado River just below this site.

Measurement site View upriver

Station #7 – Blair Ranch Rest Area, Colorado

Measurement site

Station #8 – Shoshone Power Plant below outlet from plant, Colorado

Power Plant

Measurement site

Power Plant outlet flow

Station #9 – Glenwood Springs Delivery Road – below Roaring Fork inflow, Colorado

Upriver view and USGS flow gage

Station #10 – Highway 340 near Fruita, Colorado

Muddy water with a green frog looking towards camera

Station #11 – Big Bend, Utah

Access is situated amidst riverside plant growth and beneath the high red rock cliffs of the Colorado River canyon. Average precipitation < 10 inches/year

Station #12 – Upper Lake Powell at Farley Canyon, recreational road 630 off highway 95, Utah

Navajo sandstone is the dominant formation here, formed by sand dunes hardened by the pressure of deposits overlying them. Hite Marina is just north of Farley Canyon. The Hite boat launch was closed due to low water levels.

Station #13 – Lower Lake Powell, above dam and marina on north side, Utah

The construction of the Glen Canyon Dam and Lake Powell contributed to the birth of the modern environmental movement.

Station #14 – Below Glen Canyon Dam at Lee’s Ferry day use area, Utah

The soft shale deposits create gently sloping cliffs, as opposed to the limestone and sandstone encountered upstream. This made it a good place to access and cross the river via ferry. This is also where the Grand Canyon officially begins and is the dividing point between the upper and lower Colorado River basin.

Station #15 – South Cove, Arizona

(Pearce Ferry dock is dry due to low lake levels)

Site is located in upper Lake Mead

Station #16 – Temple Bar, Arizona

Station #17 – Boulder Beach above Hoover Dam, Arizona

Station #18 – Willow Beach below Hoover Dam, Arizona

Measurement site was right below Willow Beach National Fish Hatchery, established in 1962. Fish Hatchery utilizes the cold water released from Hoover Dan to raise rainbow trout, razorback suckers, and bonytail chub. There is also the municipal inflow drainage from the Las Vegas Wash near this point. Non point source contamination from uranium mining and perchlorate contamination from rocket fuel manufacturing also start to be introduced to the river via groundwater inflow. Selenium continues to be an issue in Arizona, as it has in Colorado, Utah, and probably Mexico.

Fish Hatchery at Willow Beach

Station #19 – Right above Davis Dam, Arizona

Site was right next to the dam.

Station #20 – Below Davis Dam, Bullhead Community Park beach area, Arizona

Station #21 – Below Wildlife Refuge outflow in muddy plume, Arizona

Site measurement was made right over highway crossing, intercepting a muddy plume that was entering the Colorado River from the Topock Marsh. This wildlife refuge consists of Topock Gorge, south of the junction of Interstate 40 and the Colorado River (it is accessible only by boat or on foot) and Topock Marsh, which begins north of Interstate 40 on the Arizona side of the Colorado River and continues for 11 miles. Also included is the 18,000 acre Havasu Wilderness Area. The 37,515-acre refuge is the home of some of America's rarest birds, the Southwestern Willow Flycatcher and the Yuma clapper rail. Other species sheltered at the refuge include migratory birds, beavers and bighorn sheep.

Station #22 – Cattail Cove, Arizona

Station #23 – Below Parker Dam (Lake Havasu), Arizona

Lake Havasu provides water for a portion of Los Angeles and for most of San Diego. This water gets transported 250 miles across California! Phoenix and Tucson also tap into this water source via a mountain tunnel and an aqueduct.

Station #24 – South of Ehrenberg, Arizona

Site is located just south of intestate 10.

Station #25 – Picacho State Park, California

Station #26 – Below Yuma, before Mexico, Arizona

Site is located just west of where highway 95 changes from an east-west direction to a north-south direction. This portion of the river represented the international boundary between the U.S. and Mexico. It was hard to find an access point and I am sure we were on private property when we finally did. The border patrol was monitoring this boundary with a small airplane and a helicopter. The small airplane noticed me first in the river and did a couple of flybys. Once in the vehicle, the helicopter came in for a closer view. We could see his gun and binoculars as he paralleled us on the road. Then he left us alone. However, we then noted a border patrol truck driving in on the road we entered (we left a different route), driving rather fast. It was rather exciting since we knew we had not done anything illegal, or so I hoped.

The river looked like a stream, at this point, with a narrow width (I could have thrown a rock across) and shallow depth rising no higher then mid-calve. The water was warm and looked very clear. I did not see any fish or find any macroinvertebrates. However, I did not spend a lot of time looking either. Banks on both sides were covered in heavy vegetation. Unfortunately, there wasn’t a representative picture on the internet to use.

Station #27 – Mexico canal near old Colorado River channel bed, Mexico

The Morelos Diversion Dam, located on the Mexico-Arizona border, is the last dam constructed on the Colorado River. This dam sends all the remaining water to irrigation canals in the Mexicali Valley and to the towns of Mexicali and Tijuana. The old Colorado River bed is still very prominent however, instead of water flowing through it, it now has been turned into a landfill along its route. We crossed the channel at three locations and the story was the same. I found this very depressing after having followed the river through all its grandeur and beauty. The nearby drainage canal was a compromise to my original wish to find the water resurface in the original channel. The drainage ditch was also surrounded by trash. I even noted a dead dog lying nearby. The water itself was very suspect. I certainly was not happy about contaminating my equipment and had no desire in inserting my hands in the cesspool. I used the probe for conductivity, salinity, total dissolved solids, and temperature. A quick sample of the water was placed in the sample bottle. But, I drew the line with dissolved oxygen which requires a total submersion of my hand while holding the sample bottle for three minutes. I did note some small fish swimming around in the water and I gave them a lot of credit.

Here again I could not locate a photo to use, on the other hand, perhaps that is to our favor.

Station #28 – San Felipe area, ocean water, Mexico

We camped right on a bluff located right next to the beach. Water was very shallow for about a half mile out. The water here is very salty, 38 ppt versus a normal range of 33-34 ppt. This high salinity has adversely affected some of the organisms that live in this zone.

Water Quality Parameters and the Colorado River

Temperature can be a problem for organisms if it gets too high. High water temperatures can be unhealthy for fish, wildlife, and certain plants, and promote the growth of bacteria and viruses. The maximum tolerable temperature for fish, plant, and insect survival is 20 degrees Celsius. Temperature is a measure of how cool or how warm the water is, expressed in degrees Celsius (C). Temperature is a critical water quality parameter, since it directly influences the amount of dissolved oxygen that is available to aquatic organisms. Water temperature that exceeds 18 degrees Celsius (for Class A Waters) has a deleterious effect on several fish species in streams. Salmonids, for example, prefer waters of approximately 12 to 14 degrees Celsius. Trout prefer waters of approximately 10.5 to 18 degrees Celsius. Measurements for this study were mostly taken from the banks of the river since I did not have access to a boat. This would result in unusually high temperatures which would not correctly represent the whole river. Colder temperatures would be found at depth or within the portion of the channel that is moving rapidly. The shallower and lower velocity zones found at the sides of the river would be warmer due to the longer exposure to the sun. One notable temperature feature was the differences in water temperatures above and below the dams. The water released from the dams comes from the bottom portion of the reservoirs and is very cold relative to the surface temperatures measured from the reservoirs.

Excess nutrients – mostly nitrogen and phosphorus - can be harmful to the health of the river system. For example, nitrogen is toxic in sufficient concentrations. Also, nitrogen and phosphorus increase the growth of microscopic aquatic animals and plants which, in turn, lower the water’s natural dissolved oxygen levels. Low oxygen levels end up suffocating organisms that need oxygen to survive. Sewage is the main source of nitrates and phosphates added by humans to water. Sewage enters waterways through inadequately treated wastewater from sewage treatment plants, in the effluent from illegal sanitary sewer connections, and from poorly functioning septic systems. Two other important sources of nitrates and phosphates in water are fertilizers and the runoff from cattle feedlots, dairies and barnyards. In addition, detergents with phosphates were a prime source before manufacturers developed phosphate-free alternatives. High levels of nitrates in Lake Powell could be due to all the house boats and to other heavy usage that the reservoir receives every year. Nitrate levels are contained in the upperstratification of the lake and are not released down stream from the dam. High level of phosphates in Mexico could be from sewage, fertilizers, or detergents still containing phosphates.

"Potential of hydrogen", or the pH, is a measure of the concentration of hydrogen ions in the water. This measurement indicates the acidity or alkalinity of the water. On the pH scale of 0-14, a reading of 7 is considered to be "neutral". Readings below 7 indicate acidic conditions, while readings above 7 indicate the water is alkaline, or basic. Naturally occurring fresh waters have a pH range between 6 and 8. The pH of the water is important because it affects the solubility and availability of nutrients, and how they can be utilized by aquatic organisms. Brown trout prefer pH values in the range of 6.8-7 but they can tolerate pH values as low as 5 and as high as 9.5. Aquatic insects thrive at levels between 6 to 7.5. Sources of changing pH levels can be from mine drainages, acidic rocks (granite), or acid rain. Suggested healthy levels for a river system range between 6.5-9 (River Watch). All my measured pH values were within this suggested range.

Dissolved oxygen is the amount of oxygen dissolved in water, measured in milligrams per liter (mg/L). This component in water is critical to the survival of various aquatic life in streams, such as fish and macroinvertebrates. The minimum amount of dissolved oxygen is 6 mg/l with optimal levels for trout ranging from 9-12 mg/l. The ability of water to hold oxygen in solution is inversely proportional to the temperature of the water. For example, the cooler the water temperature, the more dissolved oxygen it can hold. In addition to temperature, dissolved oxygen is affected by velocity, altitude, and organic matter. Higher water velocities increase the amount of dissolved oxygen. There is less dissolved oxygen at higher altitudes due to decreased air pressure. Finally, more organic matter in the water leads to less dissolved oxygen. Dissolved oxygen levels in the Colorado River ranged from 6.8 mg/l in Fruita to 10.3 mg/l in Cattail Cove, all above the 6 mg/l minimum. The differences in the values were influenced by the time of day I made the measurement and the movement of the river at the point of my measurement. Perhaps the low value at Fruita was influenced by the large amount of sediment in the river that did not allow much light to enter the water, making it virtually impossible to support plant life and generate a good source of oxygen.

Conductivity is the ability of the water to conduct an electrical current, and is an indirect measure of the ion concentration. The more ions present, the more electricity can be conducted by the water. This measurement is expressed in microsiemens per centimeter (uS/cm) at 25 degrees Celsius. Chlorides, nitrates, sulfates, phosphates, sodium, magnesium, calcium, iron, and aluminum are some examples of ions that increase conductivity values. Fruita and Mexico are the two areas with either high nitrates or phosphates and we do see a corresponding increase in conductivity for both these sites. Conductivity levels increase as we go from the headwaters to the ocean. So does salinity, which causes an increase in conductivity. Sites 9-11 jump up faster in conductivity values which is probably related to the heavy agricultural activity along that section of the river. Agricultural activity will increase fertilizer runoff, increasing conductivity. The local geology, consisting of marine rocks, also plays a big factor in the increased salts that are transported to the river.

Total dissolved solids (TDS) is a measure of all the dissolved and suspended solids that are in the water. This is an indicator of non-point source pollution problems associated with various land use practices. The TDS measurement is expressed in (mg/L). Some dissolved solids come from organic sources such as leaves, silt, plankton, industrial waste and sewage. Some dissolved solids come from inorganic materials (such as rocks and air) which may contain calcium bicarbonate, nitrogen, iron phosphorus, sulfur, and other minerals. Many of these materials form salts. A constant level of minerals in the water is necessary for aquatic life. Changes in the amounts of dissolved solids can be harmful because the density of total solids determines the flow of water into and out of an organism's cells. Many of these dissolved solids contain elements, such as nitrogen, phosphorus, and sulfur, that are the building blocks of molecules necessary for life. Concentrations of total dissolved solids that are too high or too low may limit growth and lead to the death of many aquatic organisms. High concentrations of dissolved solids may also reduce water clarity, contribute to a decrease in photosynthesis, combine with toxic compounds and heavy metals, and lead to an increase in water temperature. Sources of harmful dissolved solids are runoff from urban areas, road salts, fertilizers and pesticides, wastewater, decayed plant and animal matter, construction that disturbs the soil, and clear-cutting trees which leads to increased soil erosion. TDS values followed a similar pattern shown in the conductivity and salinity graphs which would indicate the influence on increased salts along the rivers drainage route. Salts are absent near the headwaters so conductivity and TDS values probably represent the influence of the local geology in those sites, as well as variations between conductivity and TDS relative to salinity in the other down river sites.

Salinity is a major quality problem for the Colorado River. Salts are naturally occurring components that dissolve easily in water and change its quality. Salinity is measured in parts per thousand. Damage to plants occurs at .7 - .85 ppt. Ocean water has about 3.5 ppt. The section of the river below Yuma had a value of .8 ppt and I did not notice any plant life at the bottom of the shallow stream. The sites in Arizona are approaching the maximum levels that harm aquatic plants. As I mentioned in the earlier part of this report, measures are already underway to reduce salinity levels in the Colorado River.

Turbidity is a measurement of the clarity of the water. It is the amount of solids suspended in the water. It can be in the form of minerals or organic matter. It is a measure of the light scattering properties of water, thus an increase in the amount of suspended solid particles in the water may be visually described as cloudiness or muddiness. Turbidity is measured in Nephelometric Turbidity Units (NTU). Increased turbidity can affect a stream and the organisms that live in it in many ways. Suspended solids may cause the water color to change. Turbid waters usually become warmer as suspended solids which darken the water absorb heat from sunlight. Warm water holds less oxygen than cold water, so oxygen levels will decrease (as seen in Fruita). Suspended solids reduce the amount of light that can pass through the water. As less light penetrates the water, photosynthesis slows releasing less oxygen into the water. If light is blocked to bottom dwelling plants, they will cease to produce oxygen and will die. As they decompose, bacteria will use up even more oxygen from the water. Suspended solids can clog fish gills, reduce their growth rates, decrease their resistance to disease, and prevent proper egg and larval development. As particles of silt, clay, and other organic materials settle to the bottom, they can suffocate newly hatched larvae. Settling sediments can fill in spaces between rocks which could have been used by aquatic organisms for homes. Causes of high turbidity could be from soil erosion, waste discharge, urban runoff, flooding, dredging operations, channelization, increased flow rates, algae growth, or the result of stirred up bottom sediments. Fruita’s measurement exceeded the measurement limit of the turbidity meter. However, just looking at the water at Fruita revealed extremely high amounts of suspended solids. Fruita is an area of high agricultural use so sediment loading probably occurs every time it rains. Granby Lake, Blair Ranch, Shoshone, and Mexico were other locations of higher turbidity (although not near as much as Fruita). Granby Lake is in a large valley so runoff could be a possible cause. Sediment loading at Blair Ranch and Shoshone could be due to the narrow channel the river flows through at those sites, concentrating sediments. Mexico’s channelization, waste discharge, and methods in water usage are likely candidates for high turbidity values.

Applications to the classroom:

In the past I have involved my students in the adoption of a local river through River Watch. Students collected and analyzed the river water on a monthly schedule. At the end of the school year they each compiled a report that discussed the project, analyzed the data, and explained and summarized the results. I plan to expand this type of project to involve an analysis of the watershed that the river resides in and apply the information to the data collected at the river site. This Colorado River project summary will be an example of what the process might look like.