Episode list

The hundred year flood concept is important in the United States because it determines coverage for the National Flood Insurance Program. The program covers real estate that is likely to be flood once every one hundred years or equivalently has a one percent change of flooding in any given year.

Sinkholes are caused by the great eroder, water, flowing below ground level. As the water from an underground stream or broken drainage pipe flows it dissolves or simply washes away subsurface soil creating a cavern. When the cavern reaches the surface the undisturbed top layer collapses into the sinkhole.

Water towers store water to meet peak demand avoiding the need to additional pumps. And by refilling overnight they take advantage of off peak energy.

A weir is a dam that allows water to flow over the top. Their intent is to maintain water levels upstream from the weir at a stable level. But water flow in a river is not constant so hydrology engineers have a few tricks to handle changes in water flow.

We consumers receive electricity through the electrical grid which has a variety of devices producing electricity. Solar energy is unique among them in not having any inertia to satisfy peak loads. Most of the remaining devices, nuclear, fossil fuels, geothermal convert heat to steam to spin a turbine. The exceptions are wind and hydro which use kinetic energy to spin a turbine.

Grady demonstrates the variables in pipe manifolds that cause pressure loss such as length and diameter. Using an experimental rig complete with flow and pressure gauges he predicts pressure loss using the Hazen-Williams equation and Minor Loss equation.

Explained here is the relationship between pressure and flow when pumping a fluid.

Priming, cavitation and vortices all involve air in a pump and can cause it to fail, sometimes permanently. Liquid pumps can't pump air so they need to be primed (filled) with liquid when started. Cavitation is the formation and collapse of bubbles which damage the impeller. Vortices allow some air into a pump making it less efficient.

The Arecibo telescope was a unique structure operating in a unique and sometimes adverse environment which ultimately caused its collapse though in stages. Here's what happened.

Like most of the high rises in San Francisco, the Millennium Tower is build on a foundation of clay using friction piles. But the Millennium Towers load is particularly high and removing ground water has accelerated the settling much more than expected. The solution now underway is to add external piles down to bedrock.

Engineers use retaining walls to prevent earth from moving at construction sites. But it isn't as simple as building a wall. Retaining walls have to be anchored. There are several effective ways to do so but the earth may still offer some surprises.

Electrical power tends to have a mind of i's own traveling according to the laws of physics rather than human instructions. It is up to grid controllers to match supply and demand. But in Cleveland in 2003 their computer alarms were offline so they were working blind to a grown series of failures.

San Antonio's water resources range from drought to flash flood. Grady provides a tour of the city's water resource management systems. Since they were designed to be harmonize with nature his tour also includes many of San Antonio's parks.

Graound water seepage has caused catastrophic disasters in various was to large structures such as dams. But it also needs to be considered for small structures.

Grady busts construction myths about idle workers, planned obsolescence, Roman concrete, lowest bidders and bedrock foundations.

The drought in the American Southwest has created concern about their reservoirs running dry. Generally that means using more expensive sources of water.

Grady takes a closer look at what the vandals who shot up the Moore county substation where targeting and how much damage was done.

An explanation with practical examples of what an electrical ground is, how it works and how it's used even when it's not actually the ground.

If you miss the clickety clack of a train rolling along on its track, its gone because railroads switched to continuous welded rails. And not because passengers were complaining but because every click and clack caused a little bit of wear and tear on the train and track that added up to lots of money.

The diverse assortment of bridges that architectural engineers have come up with, each with its particular advantages and, more often than not, a touch of beauty and uniqueness.

Controling subsurface water is essential to the integrity of any structure. The solution engineers most often turn to is the french drain.

From the beginning of deciding where to put a landfill to ultimately closing it, a landfill is complicated. It can also have benefits beyond keeping trash out of site.