Overview
Water is life. But too much water is a flood, and too little is a drought. Water Resources Engineers manage the flow of water. They build dams to store it, canals to move it, and levees to stop it.
Core Idea
The core idea is The Hydrologic Cycle. Understanding how water moves through the atmosphere, land, and ocean, and intervening to make it useful for humans.
Formal Definition
The quantitative study of the hydrologic cycle and the design of systems to manage water resources. Key Concepts: Hydraulics, Hydrology, Fluid Mechanics.
Intuition
- The Bathtub: A reservoir (lake behind a dam) is a giant bathtub. Rain turns the faucet on. The river is the drain. The engineer controls the plug. If the tub gets too full, they have to open the drain (Spillway) or the water will spill over the edge and destroy the house (Dam Failure).
Examples
- The Netherlands: A country that should be underwater. They built a massive system of dikes and pumps (The Delta Works) to keep the North Sea out.
- California Aqueduct: Moving water 700 miles from the wet north to the dry south.
- Stormwater Management: Designing cities so that rain soaks into the ground (Permeable Pavement) instead of flooding the streets.
Common Misconceptions
- We are running out of water: We have the same amount of water as the dinosaurs. The problem is it’s in the wrong place (ocean) or it’s dirty.
Related Concepts
- 100-Year Flood: A flood that has a 1% chance of happening every year. (It can happen two years in a row).
- Virtual Water: The water used to grow your food. (1 burger = 600 gallons).
Applications
- Climate Change: Making storms wetter and droughts drier. Engineers have to redesign everything for this new reality.
Criticism / Limitations
- Ecological Damage: Dams kill fish (Salmon) and stop sediment from reaching the ocean (eroding beaches).
Further Reading
- Cadillac Desert (Reisner). A history of water in the American West.