Science Unit 5 Lesson 10

Question 1

What does the Federal Emergency Management Agency (FEMA) do?

Answer 1

Provides assistance to individuals who have suffered losses due to federally declared disasters.

In 2018, it also provided $70 million to support flood mitigation efforts in communities that experience frequent losses of property due to flooding. FEMA estimates that every dollar spent on disaster mitigation results in a savings of six dollars on disaster response.

Question 2

When old flood mitigation strategies fail, cities must decide what strategies to use in the future. Who do the cities work with to implement new flood mitigation techniques?

Answer 2

the FEMA and other organizations

Question 3

In the city of Grand Forks, ND, why did it flood?

1997

Answer 3

The land around the red River, which is near, was flat. During the winter of 1997, Grand Forks received 98 inches of snow— three times its normal annual snowfall. In April of 1997, a rapid spring thaw caused the snow to melt quickly. The water moved over the still-frozen land and into the Red River. Despite using over 3.5 million sandbags in an effort to protect the city, the river reached a level of 26.2 feet above flood level and flowed over the sandbags. Once the water flowed over the sandbags, it spread out more than 2 miles inland alongside the river.

Question 4

In the city of Grand Forks, ND, what damage was left by the flood?
(1997)

Answer 4

• Because the flooding was anticipated, the evacuation order sent out early. 90% of the population of 52,000 people were evacuated. No lives were lost.
• 83% of the homes and 62% of the commercial buildings were damaged or destroyed. 11 historic buildings burned in a fire.
• There was no running water for 13 days and no drinkable water for 23 days.
  The combined damages to the Grand Forks area totaled $1.5 billion.

Question 5

After the flooding, the city of Grand Forks worked with… who?
(1997)

Answer 5

After the flooding, the city of Grand Forks worked with FEMA, the US Army
Corps of Engineers, and other organizations to instigate several flood
mitigation projects.

Question 6

What changes were done to the city of Grand Forks after the flood?
(1997)

Answer 6

• 1,187 damaged dwellings and other structures were removed from floodplain
  areas.
• Over 800 additional properties in floodplain areas were purchased in a
  voluntary buyout program.
• A systems of new dikes was constructed on both the North Dakota
  and Minnesota side of the river.
• Nine and a half miles of diversion channels were built to direct water
  around the city during times of flood.
• Twelve new flood pump stations were constructed.
• Extra protection was provided for critical infrastructure, such as the city’s
  water treatment plant.
• New buildings were elevated with critical systems and documents housed on higher floors.

Question 7

In the city of Grand Forks, after the flood how did it improve? Describe the Greater Grand Fork Greenway.

Answer 7

A major flood mitigation effort was turning the floodplain along the river
into an area called the Greater Grand Fork Greenway. The Greenway provides an area for river water to safely spill during times of flooding while providing a popular recreational area to be used at other times. The Greenway is about 2,200 acres of open space. It features multiple parks, 2 golf courses, campgrounds, over 20 miles of trails, areas for fishing and snowmobiling, and areas for sports such as basketball, volleyball, and hockey. The Greenway has allowed for the restoration of native stream bank vegetation and wildlife

Question 8

In Grand Forks, how much money was spent on flood mitigation?

Answer 8

In total, $409 million was spent on flood mitigation efforts in the Grand Forks area.

Question 9

In Grand Forks, how much money was spent on the Greenway alone?

Answer 9

$22 million alone was spent on the Greater Grand Forks Greenway, which included the buyout or relocation of hundreds of homes.

Question 10

How did the Greenway help regain the population in Grand Forks?

Answer 10

Residents and tourists alike take advantage of the recreational opportunities of the Greenway, a newly designed town square, and a new convention center that can also serve as a disaster-staging area.

Question 11

How could a relatively small city like Grand Forks be a model for other communities that are at risk of flooding?

Answer 11

Grand Forks developed flood mitigation techniques that have been shown to reduce damages. Developing the floodplain into an open green space is a technique that could serve as a model for other communities. The city could also share its lessons learned about recommended ways to coordinate volunteers, distribute emergency supplies, establish points of contact with relief agencies, document all files and actions, and communicate progress.

Question 12

In 2005, what caused New Orleans to flood?

Answer 12

Hurricane Katrina, Huricane KAtrina began as a tropical depression in the Caribbean in August of 2005. By the time it reached the Gulf of Mexico, it had
become a Category 5 hurricane.

Question 13

Describe the flooding the occurred in New Orleans.

2005

Answer 13

Winds of speeds over 120 mph pushed seawater into Lake Pontchartrain and Lake Borgne, which border New Orleans. The seawater, combined with the roughly 10 inches of rainfall that occurred at the same time, caused the lakes to flood and many of their levees to fail 53 breaches occurred in the levees
surrounding the city, many due to flaws in either the levees’ design or in
their lack of completion. Water poured into the areas of the city that were below sea level, most of which were lower-income communities.

Question 14

What was the damage in New Orleans caused by the hurricane?

2005

Answer 14

• The devastation to the city was massive. Roughly 80% of New Orleans was flooded, in some cases by water up to 20 feet deep.
• Over 800,000 housing units were
  damaged or destroyed.
• Nearly all of the major roads became impassable, hampering evacuation.
• Tens of thousands of people who did not or could not evacuate were
  left stranded without food or shelter and required rescue.
• Physical damages were estimated
  at $70 billion. It is estimated that
  1,464 people died.

Question 15

Who helped New Orleans with the recovery plan?

Answer 15

When the city was ready to rebuild its flood mitigation system, major studies were completed first by several agencies, including the state of Louisiana and the Army Corps of Engineers.

Question 16

New Orleans had a slow start to work that the studies agreed on. Why?

Answer 16

Lack of funding and political infighting

Question 17

How long did the take for the recovery work to being in New Orleans?

Answer 17

It was seven years after Hurricane Katrina that a master recovery plan was finally agreed upon and the majority of the work began.

Question 18

What is a levee?

Answer 18

an embankment built to prevent the overflow of a river.

Question 19

Describe the recovery plan in New Orleans after Katrina?

Answer 19

The levees were raised back to their full height, and those that had never
been properly built to specifications were rebuilt to conform. Heavy rock or
concrete was added to the sides of many levees to help them withstand strong waves. Ineffective flood walls were replaced with improved designs with wider bases. The Mississippi River–Gulf Outlet Canal, which had amplified storm surges during the hurricane, was permanently
closed.An enormous floodgate, called the Seabrook Floodgate, was built across the Industrial Canal to protect the surrounding area from a surge of water from Lake Pontchartrain during a storm.

Question 20

What was the Gulf Intracoastal Waterway West Closure Complex in New Orleans?

Answer 20

One of the most impressive flood mitigation projects was the Gulf
Intracoastal Waterway West Closure Complex built at the juncture of two
canals just outside of New Orleans. It consists of a floodgate through which
boats are able to pass, 350 miles of levees and flood walls, the largest pumping station in the world, and other components. It is designed to pump water at a rate of 19,140 cubic feet per second. The complex is designed to protect three parishes (similar to counties in other states), including Orleans parish, which shares the same boundaries as the city of New Orleans.

Question 21

What is known as one of the most impressive flood mitigration projects?

Answer 21

In total, the local, state, and federal governments spent more than $20 billion on roughly 350 miles of levees, pumps, gates, and flood walls surrounding greater New Orleans.

Question 22

How much money did the Army of Corps of Engineers alone spend on projects in New Orleans?

Answer 22

The Army Corps of Engineers alone spent $14.5 billion on projects.

Question 23

Why does New Orleans have to be constantly monitored and maintained even after the recovery?

Answer 23

Because much of New Orleans is below sea level, flood mitigation projects will need to be constantly monitored and maintained.

Question 24

Has the population returned to New Orleans after Katrina?

Answer 24

The population of New Orleans, which was 484,674 at the time of Hurricane Katrina, dropped by half soon after the flooding. It has since increased to 369,000, but many who left because of Katrina never returned. The city has created improved disaster plans to respond more quickly in the event of a future flooding in order to better protect and retain its citizens.

Question 25

Flood mitigation strategies can have both benefits and costs.

Answer 25

• They can mean lower costs for flood insurance, while also creating higher taxes.
• The projects themselves provide employment, but their location may damage a business or industry.
• They can generate public spaces, such as the Greater Grand Forks Greenway, but also result in the relocation of homes.
• They can revitalize certain industries, such as tourism and fishing in New Orleans, but require continual maintenance costs.

Question 26

Think about the differences in each city’s location and the causes for potential future flooding. Why was a major approach in Grand Forks to move people away from the river, while the main approach in New Orleans was to build or reinforce structures?

Answer 26

Grand Forks has flat land located near a river. The city’s main concern was the overflowing of the river onto the floodplain where houses were located. Moving these houses off the floodplain helped mitigate future damage to homes. New Orleans is located next to the Gulf of Mexico. Its main concern was future hurricanes and storm waves. The city needed to build and reinforce structures in order to protect their city.

Question 27

Consider the points made by the blogger. How do the benefits of flood mitigation compare to the costs for both Grand Forks and New Orleans?

Answer 27

In Grand Forks, many people had to relocate their homes as part of the flood mitigation efforts. Some had to move to a completely different home. The town spent $409 million on projects to protect Grand Forks. However, the benefits of protection from future floods and as well as not needing to relocate homes will almost certainly outweigh the cost of flood mitigation. In New Orleans, over $20 billion was spent on flood mitigation projects. The benefits of these projects include the prevention of loss of life and property. Important industries, such as fishing and tourism, benefit from people’s confidence in the flood mitigation projects’ ability to keep the city safe.

Question 28

In 2017, what caused Houston to flood?

Answer 28

Hurricane Harvey

Question 29

What was the cost of the damage during the flood in Houston?

2017

Answer 29

$125 billion

Question 30

What makes Houston susceptible to flooding?

Answer 30

The city of Houston is barely above sea level. Its flat terrain makes it incredibly susceptible to flooding.

Question 31

Flood control officials in Houston are currently working on a number of flood mitigation projects. Which project helps storm water?

Answer 31

One project is to increase storm water conveyance capacity. In other words, the goal is to increase the movement of water by adding features such as pipes, inlets, ditches, and depressions.

Question 32

Flood control officials in Houston are currently working on a number of flood mitigation projects. Which project involves storm water detentions?

Answer 32

Another project is to create storm water detention basins, which are useful in areas located near bayous, marshy outlets. The basins are designed to receive and hold above-average storm water volumes. When the possibility of flooding no longer exists, the basins slowly release the water back into the bayou.

Question 33

Flood control officials in Houston are currently working on a number of flood mitigation projects. Which project involves desilting reservoir weather sheds.

Answer 33

Houston officials are also working on desilting reservoir watersheds. Desilting is the removal of earthy matter or fine sand left by moving water. This sediment can cause blockages or obstructions.

Question 34

What are the cost of the projects in Houston?

Answer 34

$2.5 billion

Question 35

Describe the benefit-cost ratio.

Answer 35

Economists use a benefit-cost ratio to help evaluate whether an action is successful. The benefit-cost ratio is the total monetized benefits divided by the total monetized costs. An action is a considered to be a success whenever the benefit cost ratio is greater than 1.

Question 36

Why is an action considered to be a success if the benefit-cost ratio is greater than 1?

Answer 36

If the ratio is greater than 1, then the total monetized benefit is greater tan the total monetized cost.

Question 37

Why is it difficult to attach a monetary amount to air pollution resulting from flood damage?

Answer 37

The costs of air pollution are not always immediately obvious or easy to pinpoint. Some people may develop health issues as a result of the air pollution, but the symptoms may not show up immediately or be easy to attribute to a single source. Local wildlife may suffer ill health, have difficulty reproducing, or die as a result of the air pollution, but it can be a challenge to both track the issues and separate out air pollution resulting from a flood as the sole cause of the problems. In both of these examples, any dollar amount assigned could be considered subjective.

Question 38

Why did Grand Forks undertake a major mitigation project based on relocating homes off of the floodplain?

Answer 38

Grand Forks is in a rural area with room for expansion away from the river. The cost to repair or rebuild homes on the floodplain would ultimately be more than the cost of relocating them. By moving the homes, the floodplain could return to its native state and do a better job of absorbing floodwater.

Question 39

Why were the mitigation projects in New Orleans primarily focused on building and improving physical barriers

Answer 39

New Orleans is an urban city with less ability to relocate homes. Its location near the Gulf of Mexico puts it at risk for storms with strong winds that cause seawater to blow inland and that stress physical barriers. Strengthening physical barriers offers the best protection for the residents.