DAMS DAMS &&

DIKES/LEVEES DIKES/LEVEES

JACK FORRISTEL

1.2M Square miles (CA is 158,647 Square miles)

Santa Clara Valley WatershedSanta Clara Valley Watershed

• 5 individual watersheds

• 10 reservoirs

• 168,914 af storage capacity

• 3.7% of Shasta

• 0.6% of Lake Mead

Headwaters Of The Mississippi River

Lake Itaska, MinnesotaLake Itaska, Minnesota

The RiverThe RiverEnd To End

• 2,341 mi long• 3rd largest in world• One drop takes 90 days to reach the

Gulf• Flow is 1.2 mph at source and 3 mph

at mouth• 1,475 elevation drop from top to

bottom

MississippiMississippiDeltaDelta

• 7,000 years to create. 80 years to control.

• Note channel which has “meandered” over the years.

• 5.5 MGPS (= 46’ deep x 1228” long x 230’ wide pools every secondevery second).

• 160M Tons of sediment per year exit the delta and is deposited beyond the continental shelf.

Interesting FactsInteresting Facts

• 1927 floods covered 27,000 sq mi, caused 200 deaths and displaced 600,000 people.

• Congress mandated Corp Of Engineers to control flooding and enhance navigation. Dams and dikes/levees followed.

• At New Orleans, river is 1/2 mile wide and 200 ft deep.• Total system has 12,300 miles of waterways.• River is navigable to Minneapolis-St. Paul.• Opened central US to foreign markets and provided

competitive/economical transportation system.• Carries 160,000,000 tons of sediment per year to the Gulf. Most flows

over the continental shelf to deep water rather than being dispersed and deposited within the wet-lands.

Dams On Upper RiverDams On Upper River

• 29 dams on upper river control depth to 9 ft min

• Specifically installed to aid navigation - not flood control

• During floods, gates are opened

• Each dam has locks attached• Tributaries have dams to

control flooding & aid navigation

Reasons For DammingReasons For Damming

Bonneville Dam, Oregon

Flood Control

Mississippi River

Navigation

Reasons For DammingReasons For Damming

AlmadenCommunity Water-Recreation

Hetch Hetchy Community Water (Only)

Reasons For DammingReasons For Damming

Shasta Dam Hydroelectric Generation

Negative Impacts of Dams & Negative Impacts of Dams & LeveesLevees

• Fisheries may be interrupted by interfering with spawning and water temperatures changes.

• Takes away land from other uses

• Potential for precluding archeological research

• Detract from natural setting

• Increased evaporation of surface water

• Silting effects all dams

• Other you may think of

Levee TypesLevee Types

• Mainline & Tributary Levee: Parallels main channel

• Ring Levee: Encircles an area• Setback Levee: Backup to existing levee• Sub Levee: Control under seepage• Spur Levee: Protects main levee by directing

current riverward

Levee ConstructionLevee Construction

LeveesLevees

• Mississippi River has 1,602 miles of 25 ft high levees• Sacramento Delta has 1,100 miles of 20 ft high levees

controlling flow or isolating land from five rivers: Sacramento - San Joaquin - Mukelumne - Cosumnes - Calaveras

• 47% of states total water runoff flows through the Sacramento Delta

• South Bay has many miles of very low levees which isolate the evaporation ponds

Commerce

• 12 rivers support the commerce of the river system. They are the Ohio, Missouri, Illinois, Arkansas, Tennessee, Cumberland, Green/Baren, Konawha, Kentucky, Monongahela, Allegheny, Clinch.

• Total system contains 12,300 miles of waterways.• Generates $284B annually to the economy.• New Orleans is largest grain port in the world.• Grains, coal, coke, petroleum products, sand, gravel, salt sulphur,

chemicals and others.

TransportationTransportation

• Integrated tows can be composed of 40 or more 1,000T barges carrying 200,000 barrels of petroleum. An average though would be 15 barges which is equal to a 3 mile long train or 34 miles of 18 wheelers.

• Between 31 July and 12 August there were 636 barges within the system. 321 were traveling upstream while 315 were going down stream.

JTO Dam DemonstrationJTO Dam Demonstration

• Very poor description in the teachers edition.

• From others, try 6 Fettucine, 12 Spaghetti, 3/8 C flour & 1 tsp Salt.

• Objective is to test strength of various types at constant elevation

• Let imaginations run wild