H2O a combination of two Oxygen atoms with one Hydrogen atom. Seemingly a simple concept, water is vital to all known life and is a constant challenge to human endeavors. From the oceans to the atmosphere, water controls life. Similarly, water, either frozen or liquid, is responsible for shaping the Earth’s surface and is even significant to subsurface tectonics. Some of the complex interactions between water and humans are outlined below.

• Hydrologic Cycle: Most rivers and streams are fed by rainfall. The Hydrologic Cycle involves the evaporation of water from the oceans, precipitation of that water over land, and runoff of the rainfall into streams that empty back into the ocean - hence the "cycle". We are primarily concerned with fresh water – rivers, lakes, and groundwater.
  (OVERHEAD)
• Fluvial - of, or pertaining to, Rivers - produced by river action
  (OVERHEAD) - Worlds Major Rivers by Volume
• Discharge - The volume of water carried by a river. Most often produced by rain or snow melt and measured in Cubic Feet per Second (CFS) or Cubic Meters per Second (CMS).

• Tributary - A drainage that contributes water to a larger stream or river. A drainage basin within a drainage basin.
• FOUR Major Types of Drainage Basin - Dendritic, Radial, Trellis, Glacial (complex)
1. Dendritic - Most common - like the branches of a tree - ex. Mississippi draw -

 

 

 

2. Radial - Usually associated with domes or volcanoes. A circular drainage.
   draw -

 

 

 

3. Trellis - Step like drainage due to underlying geologic structure - ex. - Utah - Arches N. P., Pennsylvania, and Mississippi tributaries in Missouri. draw - Wind/water gaps - Appalachians

 

 

 

4. Glacial - Complex and Chaotic due to overdeepening by Continental glacial ice - ex. draw - Minnesota, Canada
   (OVERHEAD) (MAPS)

 

 

 

FLUVIAL THEORIES LANDFORMS and PROCESSES - Landforms created by running water and the processes that result in those landforms.
(OVERHEAD)

Two Major Landform Categories - Erosional and Depositional.

• Erosional - Produced by the Removal of rock and debris by running water.
  ex. - Canyons, ravines, peaks, spurs, passes.
  (OVERHEAD) Often Complex - like Wind/Water Gaps - Appalachians
• Depositional - Landforms produced by the Deposition of rock, debris, sand, silt, clay.
  ex. Alluvial fans, deltas, levees, flood plains

The difference between the two types of landforms produced by running water is related to a complex interaction of factors. These factors include: stream volume, stream gradient, and the "erodability" of the underlying rock - i.e. Shales are easier to erode than Granite.

Stream Gradient - The slope of a stream - usually measured in feet per mile.
ex. - raftable streams vary from ˜ 8 (Grand Canyon) to ˜ 90 ft. per mile.
Steep stream gradients are usually erosive - When combined with increased volume (flood) can work exponentially harder - i.e. double the streams volume and you triple the volume of sediment that the stream is able to carry.
Shallow stream gradients are usually depositional - Mississippi

SEDIMENT TRANSPORT -
Erosion occurs when Physical and Chemical Weathering weaken the surface layer and form a Regolith that is susceptible to Mass Wasting. Mass Wasting (particularly Earth Failures) often deposit regolith (now sediment) into a stream channel. This new sediment is now ready to be Transported by the stream - often by the very event (i.e. heavy rain) that produced the Earth Failure. As the stream approaches Base Level, the Stream Gradient decreases and the water can no longer support the heavier sediments. This material is then Deposited.

Dissolved Load - Material carried in solution - ex. Salts, limestone to a lesser degree.

Stream Load - Solid Material carried along by the water in a stream.

Two Types of Stream Load -

• Suspended Load - Silt, clay, and sometimes sand carried within the water column - i.e. "Dirty Water"
• Bed Load - Larger particles: sand, gravel and boulders that move along the channel floor by rolling, sliding, and Saltation.

The Meandering Rivers that we are more familiar with - Mississippi - have a low gradient or are no longer eroding downward - i.e. reached Base Level.
(OVERHEAD)

Meander Migration - Involves both Erosion and Deposition.

Erosion - involves higher velocity water and centrifugal force. Occurs along the Outside of a meander
Deposition - Occurs along the inside of the meander as Point Bar Deposits
Point Bar - A bar made of sand, gravel, or boulders that is deposited along the inside of a river meander.

Cut -Off Meanders and Oxbow Lakes - created by catastrophic meander migration

draw - Meander Cut-Off                                                         Oxbow Lake Formation

Important Politically - examples Missouri River - Nebraska - Iowa (draw) also China and USSR have gone to war over cut-offs on the Amur River.

Larger particles (sand) are deposited on top of the levee as the stream velocity slows - as velocity slows stream power is reduced and larger particles drop out. Smaller particles (silt and clay) are still suspended in the water column as the flood waters overtop the levee (dirty water). Once the flood waters reach the flood plain they slow even further, and the silts and clays have a chance to settle out. Leads to Great Agriculture Land - Very Fertile (The Nile)

Sediments can also be deposited in the stream channel - this situation can lead to the river channel rising above the level of the flood plain - Dangerous (ex. Mississippi at New Orleans)

Stream Capture - The process of one drainage "capturing" the drainage of another stream. Examples - Orinoco losing headwaters to Rio Negro - Amazon
          Best Example - Atchafalaya capture of the Mississippi River

Diversion of the Mississippi River from it's present course too the Atchafalaya River -
(OVERHEAD)
         What would this do to the economies of Baton Rouge and New Orleans?

“Water is the oil of the 21st century” Carlos Guerra, San Antonio Express News, 6-20-02.

The Need for Water The average human being can survive for about three days without water. Severe dehydration leads to the loss of blood volume (the water portion) in the cardiovascular system. This in turn leads to inadequate oxygen perfusion in living tissue. There is not enough blood volume to transport all of the oxygen needed. Eventually the person becomes comatose, brain damage occurs, and the person dies.

Americans have spent trillions of dollars on water and water resources. Most of this money was used to finance the immense hydrologic network that provides water to almost every American household. Think of how the water in your tap gets there. Turn the faucet and water appears, but how did it get there, where does it go? Many scientists suggest that the advance into the Industrial Revolution was the result of our ability to deliver clean water to the general public. London’s sewer system created in the mid 1800's was truly an advance for civilization.

Our drinking water comes from the vast network of dams, aquifers, canals, water tanks, and pipes that bring water to your home. An almost equal infrastructure removes waste water and treats that water to almost healthy standards.

Americans have invested trillions of dollars to insure that we have an abundant supply of clean, fresh water. Most of this money is invested in the storage facilities, dams, forebays, off stream storage, and water tanks, as well as the transport infrastructure, canals and pipes, that bring water to your home. Another large cost is the treatment of water before it enters the municipal system and the treatment of sewage before it leaves the municipal system. In West Lafayette IN, residents pay the assessed value of water per gallon or they have private wells. In many parts of the United States, water is subsidized. For example, in most parts of California, water use is not metered and residents pay a fixed monthly fee.

Residential Water Costs

An Acre Foot is equivalent to one acre of land covered one foot deep with water. Approximately 326,000 gallons (325,851 gallons). (Enough for a family of five {four in Texas} for one year).

Farmers in the Central Valley of California pay as little as $8.00 per acre foot.

Dam Building and Hydro Projects - The United States government has financed a large portion of the nations vast water infrastructure. With the exception of the California State Water Project, all major hydro projects are funded by the federal government. The very large projects, Hoover Dam, Grand Coulee, Glenn Canyon Dam, etc. are built by either the Army Corps of Engineers or the Bureau of Reclamation.

Dam Benefits – Why build it?
Most dams have decidedly more benefits than negative impacts. In many areas, dams are the major source of water, cheap hydroelectricity, flood protection, and recreation. However, dams also silt over, change downstream sediment loads, often increase downstream erosion, drown valuable landscape, and pose a risk of catastrophic failure.

Multi-Use Reservoirs – Often a highly politicized concept

• Flood Protection – Often the main reason a dam was constructed. Reservoirs built for flood protection are drawn down to provide space for floodwaters. This leaves less volume for hydropower production, irrigation, recreation, and other uses such as maintaining adequate flow for fish species survival.
• Hydropower – A major benefit of large dams and a great source of cheap electricity. Can be a great benefit in certain areas. For example, the state of Washington generates so much hydropower that in most years it exports power to other states. This source is very dependant upon water availability and is vulnerable to drought.
• Irrigation and Water Supply – Both critical issues and in many ways inseparable. Irrigation is largely responsible for human development since the stone age and is critical to American agriculture today. Much of American agriculture is irrigated. For example, over 90% of crops produced in California are irrigated. Most of this is from surface irrigation provided by the extensive system of dams and canals. The agricultural products produced by this subsidized water system feed all of California and provide 50% of the fresh fruit and vegetables for the United States.

In California, agriculture uses about 85% of the available water, industry uses 10%, and municipal use (the people in cities) 5-7%. Other dry states, such as Texas, have similar use scenarios.

Consider the state of Indiana and where the major sources of water are:

How much of the available water is distributed to agriculture, industry, and cities?
Who should have this water?
What should they pay for water?
Who gets what during drought?

• Recreation – Still a difficult management problem defined by conflicting interests. Lakes, rivers, and creeks are a major source of hiking, boating, fishing, skiing, and other forms of recreation.

How much water should be stored or not stored?
Who should have access to which water bodies and for how long?
Who owns the banks or the beach?

Fort Peck Dam was designed and built in the 1930's and at the time was the worlds largest earthen dam. The dam holds back the headwaters of the Missouri River and the water is used to irrigate over 110,000 acres of farmland. Unfortunately, by filling the reservoir, over 100,000 acres of farmland were inundated.

When the Unthinkable Happens - The third greatest disaster in U.S. history in terms of lives lost is the Johnstown Flood. In this accident, heavy rains weakened and overtopped a poorly constructed dam upstream of the town. There were ample signs of impending failure. Over 2000 people died. A similar situation impacted Los Angeles in 1928, when a water supply dam, the St. Francis Dam, collapsed after being undermined by water pressure. The resulting flood wave drowned over 450 people.

Dams are generally thought of as unyielding, perfect structures, that are safe in all situations. However, “all dams crack” and “all cracks leak” John King – Friese Nicholls Engineers commenting on the Medina Dam July 6, 2002, Medina Lake, Texas.

Medina Dam – 176 ft. tall, built in 1913. Major floods (over the spillway) in 1917 and 2002. 2002 event was 10.3 feet above the spillway and was 1.5 feet from overtopping the dam. Major erosion of the spillway occurred. Overtopping would have destroyed the dam.

Dam failures are, unfortunately, not a rare occurrence. There is a catastrophic failure of a large dam (holding 100,000 acre ft. or more) about every decade or less. Many close calls do not even get reported to the general public.

Glen Canyon Dam - This dam is a classic example of good intentions falling victim to real world processes. The dam was completed in 1966 as a Multi-Purpose facility. It generates electricity, provides water for irrigation, and Lake Powell (the reservoir) is a world renowned recreational site. Glenn Canyon Dam is 708 feet tall and holds back 27,000,000 acre feet of water at full pool. If distributed evenly over Indiana, the 27,000,000 acre feet of water in Lake Powell would cover the entire state with over 13.5 inches of water. The concrete gravity arch has two spillways, one on each side of the dam, and a series of outlets at the base of the dam for electricity generating and emergency release. At full release, each spillway can discharge 70,000 cubic feet per second (CFS), and the outlets at the base of the dam an additional 40,000 CFS. The storage potential of the reservoir, combined with the release potential of 180,000 CFS, is enough to match or exceed any predicted flood. A significant portion of the reservoir’s storage capacity is designated for flood containment.

Dam Impacts -
The primary tributaries are the Green River, Colorado River, and to a lesser extent, the San Juan River. Before the dam was built, it was estimated that the annual average flow of these rivers was 14 million acre feet per year. Since construction, yearly flows have averaged around 7 million acre feet per year, about half of the anticipated volume.

The dam is constructed in the Navajo Sandstone Formation, which is a porous sandstone deposited in a Sahara like desert during the Jurassic. Water began seeping into the sandstone as soon as the reservoir was filled. Approximately half a million acre feet disappear into the sandstone every year. Although the seepage was predicted to stop years ago, it has yet to slow down.

Lake Powell exists in one of the hottest and driest areas within the United States. Seven vertical feet of the reservoir are evaporated every year. This is equivalent to another one half to one million acre feet removed from the surface every year.

Since the construction of the dam, annual spring snowmelts have been contained within the reservoir. The floods produced by these snowmelts previously scoured the river corridor downstream of the reservoir (The Grand Canyon). Since the reduction of spring floods, non-native vegetation, primarily Tamarisk an ornamental plant originally from the Mediterranean, has invaded the canyon corridor. The Tamarisk evapotranspire enormous amounts of water and remove an additional half million acre feet of water from the river. Additionally, the river itself looses more surface water due to evaporation.

The combined processes outline above remove approximately 2 million acre feet of water every year simply because the dam exists. This is approximately 29% of the incoming water. Additionally, water released from the reservoir is 48° F and clear. This contrasts sharply with the warm and turbid waters that enter from upstream. Not only is the reservoir silting over at rapid rates (estimates to total silt over range from 100 to 500 years), but due to the effect of the cold release water, many native fish species have become endangered. Non-native trout contribute to their decline forcing native species into very small areas near tributary streams.

Many of the engineers who designed Glenn Canyon Dam see a need to possibly remove the structure to improve downstream water supply.

In May and June of 1983, the United States nearly suffered the greatest human caused catastrophe (other than war) in our history. What was it?

During the winter of 1982/83 El Nino conditions prevailed and resulted in the migration of the Alaska low from the Gulf of Alaska to off shore of California and Oregon. Due to the position of the Alaska low, the west coast was impacted by an unusually large number of strong storms. These storms continued into the four corners states and dumped heavy snow in the mountains that supply the Colorado River and it's tributaries. Snow fall records were shattered throughout the southwest and west, with many areas receiving over 200% of their annual average snow pack. As spring temperatures rose at the end of May, rivers began to flood at previously unrecorded levels. This run off produced major problems in Salt Lake City with both city flooding and the Great Salt Lake rising and threatening to inundate I-80 and the airport. Big problems also occurred in California and along the Colorado River and it's tributaries.

Run off from the tributaries to Lake Powell exceeded 100,000 CFS in late May and began quickly filling the reservoir. The outlet pipes at the base of the dam were releasing their maximum capacity of 40,000 CFS, but the spillways remained above the level of the lake and could not help drain the reservoir. As inflow neared it's peak of 113,000 CFS, the reservoir finally filled, and for the first time since the dam's creation, water began to flow down the spillways. The first trickle of water was a media event with most of the major networks represented. As the reservoir continued to fill over the next several days, the flow entering the spillways increased to about 35,000 CFS each. Although this flow is only half of the design capacity of the spillways, this volume began to exceed the structural integrity of the spillway and loud rumbling noises could be heard emanating from the bottoms of the spillways. Engineers soon reported "house sized" boulders rolling from the spillways. If the erosion of the spillways continued, the dam would fail catastrophically.

Steel plates were placed across the spillways to prevent the water from entering. This gave the engineers time to inspect the spillways and several days to figure things out. Meanwhile, the reservoir continued to fill. Erosion in the south spillway had removed larger amounts of material, approximately as much as the volume of the Evans Liberal Arts Building. However, erosion in the north spillway had propagated further upstream and was closer to the level of the reservoir. Meanwhile, the reservoir continued to fill. The steel plates covering the spillways increased the surface level of the reservoir by another six feet. The dam was not designed to handle this much stress. During periods of high downstream winds, waves would lap onto the top of the dam. If water flowed over the top of the dam, it would fall over 700 ft down the face of the dam. It would arrive at the base of the dam with enough power to remove the outlet works at the base, undermine the dam, and release the reservoir. If Glenn Canyon Dam failed, it would release 27,000,000 (actually 32,000,000 acre feet due to blocking the spillways and raising the lake level) acre feet into the Grand Canyon. As a precaution, everyone floating the Grand Canyon on commercial or private river trips was evacuated by helicopter at government expense. The flood wave would arrive at Lake Meade within one or two days. It is very unlikely that Lake Meade could have withstood the sudden influx of so much water. The lake level would have quickly risen and overtopped Hoover Dam. Water overtopping the structure would quickly undermine and remove the dam. The combined volumes of Lake Powel and Lake Meade would overwhelm the remaining smaller reservoirs and lead to a catastrophic flood.

What would you do?

The Solution - Allowing water to flow over the top of the dam would certainly lead to a catastrophic failure of the dam. Not an option. Therefore water must be released through the only other mechanism possible, the spillways. More water was released through the south spillway even though it had suffered greater amounts of erosion. Since the erosion had propagated further upstream in the north spillway, releasing more water through that spillway "might result in the uncontrolled release of the reservoir". Finally, the inflow decreased enough to allow the lake to be drawn down below the level of the spillways. The spillways have since been repaired and holes have been drilled to the surface to reduce the process of cavitation, which led to the original erosion. The new system remains untested.

Cavitation - A process where water changes from a liquid to a gas (vapor) due to a sudden decrease in pressure. For Example, pressure decreases as water speeds over a boulder or waterfall. The water cavitates, producing bubbles, which "implode" back on themselves when the water reaches the base of the drop and pressure increases. Can be very destructive - Glenn Canyon Dam, AZ 1983. Also the process that produces bubbles from a motor boats propeller.

Vaiont, Italy - Dams do not necessarily have to fail in order to wreak havoc downstream. The Vaiont Dam is located in the foothills of the Italian Alps and was completed and filled in the early 1960's. The reservoir was nestled into a deep canyon formed within tilted sedimentary formations. When the reservoir was filled, the water saturated the sediments and lubricated the boundary between two of these layers. Evidence for the inevitable landslide failure included measured slippage rates exceeding one meter per day just days before the disaster. There was no warning to the inhabitants. The mountain (literally the mountain: one of the largest landslides in recorded human history) slid into the reservoir during the night on June?? 1963. The resulting wave spread both upstream and downstream and reached heights of over 600 feet. Villages upstream of the slide were destroyed by the initial wave and repeatedly impacted by sieche waves for many more hours afterward. Downstream of the slide, a 600 foot wall of water poured over the dam and into the valley below, destroying many villages downstream. More than 2000 people drowned that night. Remarkably, the dam did not fail.

Teton Dam - The failure of the Teton Dam provides many clues to the difficulties of environmental management. The dam was constructed by the Bureau of Reclamation just after the heyday of dam building in the United States had ended. Most of the excellent dam sites had already been located and dammed and the competing agencies were looking at the less perfect dam sites. The lithology forming the foundation of the Teton Dam was porous and had many caves. With extensive excavation and grouting, these lithologies can form safe foundations. In a hurry to beat a funding deadline, the reservoir was filled too quickly. Water was able to flow through cracks and holes in the foundation and began to erode the earth fill dam. Over the course of several hours, the escaping water eroded larger holes into the dam face until it collapsed catastrophically and released the reservoir. Although there was some warning, eleven people drowned in the flood. The reservoir has been rebuilt.

Irrigation and Water Supply Systems – Critical to the United States and increasingly worldwide. The classic example is the city of Los Angeles and its struggle to obtain and sustain an abundant supply of clean fresh water. This struggle has lasted for years and cost many lives. Many of the land purchases, water rights purchases, and other techniques used to get water to Los Angeles are of a dubious nature and are still a source of controversy. (see Chinatown – movie starring Jack Nicholas or “Cadillac Desert” by Marc Reisner). The engineering breakthroughs needed to get water to Los Angeles was incredible for the time and is still copied today.

Los Angeles Water Supply – Worlds largest water supply system

• California Aqueduct – Owens Valley California 1913 – extended 1940 - 340 miles of canals, culverts, powerhouses, and over 100 tunnels (75 miles)
• Colorado Aqueduct – Colorado River to LA – 1939 - Travels under the San Jacinto Mountains (10,804 ft high)
• Los Angeles Aqueduct – California Central Valley Plan 1970 - Increased LA water supply by 50%

River Engineering - Help or Hazard?

Army Corps of Engineers - Mean well, but often don't understand the complexity and energy involved in fluvial systems. Often destroy what they are trying to protect - Kissimmee, Florida - and/or endanger the very population that they are trying to protect. ex. Sacramento CA and the Auburn Dam project.
(not always Corps fault)

Artificial Levees - If the levee height is artificially increased, sediments cannot reach the flood plain and are deposited in the channel. The channel rises which decreases the volume available for containing floodwaters. The result is smaller floods are able to overtop the artificial levees. A major problem for New Orleans.

Mid West Floods - 1993 - we should see something similar again in our lifetimes.
(OVERHEADS) - Mid West Floods

Levees were raised in many locations - Water Could Not spread out into Floodplain - was forced to Rise - no where to go but UP. Artificial levees also increase the risk of downstream flooding - "just funnel all of that water downstream to your neighbor".

Bangladesh

Flood Tourists – New Braunfels 1998, 2002.

WATER POLITICS - Can be the most confusing and complicated management issue in existence. This is also perhaps the most important issue in Environmental Management and is a major source of future geography jobs.

Who owns the water? What are the riparian rights of people living next to the water?
             - Long Lots, Louisiana and Quebec
How much water can you remove from the stream?
How much do you have to send to your downstream neighbor?
How much must be sent to you from upstream?
What about ground water?
Who owns the Edwards Aquifer?
Do we have the right to use all of the water in the Rio Grande?
Should human interests always be placed above those of animals and plants?
Should water be released to ensure that endangered species survive?

Political Examples:

Turkey and the headwaters of the Tigris and Euphrates
    - Affects Syria, Iraq – potentially Jordan, Israel, and Cyprus

Devils Lake ND
    - Internal Drainage – will eventually drain to Canada through Stump Lake
    - Garrison Diversion
    - History

Caspian vs. Aral Seas – Stream Diversions and consequences
    - Syr and Amu Daryas
    - Don River and the Sea of Azov

Salt
    - Irrigation – Ancient problem since Mesopotamia
    - Wyoming Coal Mine Water

Irrigation Runoff
    - Kesterson National Wildlife Refuge, California - Selenium

Far cheaper than finding new sources of water. Generally, most water is used for watering landscape around the house. Toilets, washing machines, showers, and dishwashers also use much water.

- Household conservation
- Metering – gardens, swimming pools, etc.
- Grey water
- Limiting use
- Municipal incentives – rate rebate

Water will become harder to find and harder to get. This will occur even if the predicted Global Warming does not occur. If warming does occur, then the reliability of water resources and sufficient water supplies is unpredictable. The future of water is defined by one significant factor. We will die without it.

- Sources of fresh water will become fewer and more expensive
- Alternate sources of water such as desalination or water tankers will be explored
- Water managers and planners will be in high demand