Developing Structural and Non-Structural Resilience to [Mountain] Flooding

Indo-US Workshop

Folsom, CAFebruary 17, 2015

Gerald E. Galloway, Jr., PE, PhDCenter for Disaster Resilience, University of Maryland

Visiting Scholar, US Army Corps of Engineers Institute for Water Resources

Landslides

BLUF1. The Risks Associated with [Mountain] Floods

Are Increasing; Change (including Climate Change and Growth) Is a Major Influence

2. Understanding Risk and Developing Resilience through Multiple Means Mitigates These Growing Challenges

3. Governments and Society Must Both Be Fully Involved in Risk Communication and Resilience Development

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17(Comedian’s Convention)

Traditional Planning» Assumed little change – climate and human» Operated within a narrow future» Remained inside disciplinary stovepipes

Planning for a Murky Future

Present Future

Adapted from Marc Waage , Denver Water

Rational Scenarios

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Present

Future

New Approach Hundreds of possible climate and

anthropogenic-driven scenarios Shared responsibilities Adaptive, complimentary efforts Adapted from Marc Waage , Denver

Water

Dealing with a Murky Future

Traditional Approach» Assumed little change – climate and human» Operated within a narrow future» Reamined inside disciplinary stovepipes

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The Move to Flood Risk Management

A willingness to live with floods• Individual and

small communities adapt to the natures rhythm.

A desire to utilise the floodplain• Fertile land in

floodplain is drained for food production.

• Permanent communities are established on the floodplain.

A need to control floods• Large scale

structural approaches are implemented through organised governance.

A need to reduce flood damages• A recognition

that engineering alone has limitations.

• Effort is devoted to increasing the resilience of communities should a flood occur.

A need to manage risk• A recognition

that not all problems are equal.

• Risk management is seen as an effective and efficient means to maximise the benefit of limited investment.

HAZARD CONSEQUENCESVULNERABILITY

RISK MANAGEMENT STRATEGIES

RISK

EXPOSURE

RESILIENCE

Reduce physical impact of hazard-- e.g. levees; preserve and enhance natural defenses such as wetlands, flood plains

Move assets out of harm’s way--long term: through restricting development in floodplains and buyouts; short term: by evacuation

Reduce susceptibility to impacts — e.g. enforce building codes, retrofitting, harden infra-structure, education and improved communication

ResilienceThe ability to prepare and plan for, absorb, recover from or more successfully adapt to actual or potential adverse events.

Torrens Resilience Institute

Characteristics of a Resilient Nation

• Individuals and communities are their own first line of defense• National leadership in resilience exists throughout federal

government• Community-led resilience efforts receive investment and support.• Site-specific risk information is readily available, transparent, and

effectively communicated.• Zoning ordinances are enacted and enforced. Building codes and

retrofit standards are widely adopted and enforced.• A significant proportion of post-disaster recovery is funded through

private capital and insurance payouts. Insurance premiums are risk based.

• Community coalitions have contingency plans to provide service particularly to the most vulnerable populations during recovery.

• Post-disaster recovery is accelerated by infrastructure redundancy and upgrades.

.

Risk CommunicationA disciplined

process of identifying risk, developing and implementing a strategy to deal with that risk, and keeping

that strategy up to date.

Ann Azevedo, Chief Scientist

ALARP =As Low As Reasonably Practicable

WHO DECIDES?

http://www.asce.org/templates/publications-book-detail.aspx?id=78

http://www.nad.usace.army.mil/CompStudy

Flood Risk Is Increasing

The Bottom Line

Now is the time to accelerate progress and move aggressively forward to address the challenges of flood risk management.

To do so the nation must:• Develop a unified national (not federal) vision and supporting

organizational framework for flood risk management;• Define, apply, and evolve best practices in flood risk

management;• Identify and communicate flood risks to all affected parties;• Provide adequate resources to support flood risk reduction

strategies;• Focus attention on the challenges of flood risk management

Risk Reduction Measures

(Source: data from National Research Council, 2013, and the NFIP, 2013 as modified from USACE)

Other MeasuresStructural Dams Barrages/Wiers Tunnels Channel Control

» Hydraulics» debris

Levees

Non-Structural (NB) Land Planning Pluvial Control Sediment Management Elevation Deforestation Control Maintenance Wetlands Natural Storage

Balancing Natural Resources against Human Stressors

• Building Standards• Flood Standards• Sustainable Hospitals• Climate Resilience Tool Kit• Planning Guidelines

PolicyIt is the policy of the United States to strengthen the security and resilience of its critical infrastructure against both physical and cyber threats.

The Federal Government shall also engage with international partners to strengthen the security and resilience of domestic critical infrastructure and critical infrastructure located outside of the United States on which the Nation depends.

U.S. efforts shall address the security and resilience of critical infrastructure in an integrated, holistic manner to reflect this infrastructure's interconnectedness and interdependency.

February 12 2013

http://www.gpo.gov/fdsys/pkg/FR-2013-11-06/pdf/2013-26785.pdf

Federal Flood Risk Management Standard

When complying with this Order, the floodplain shall be established using one of the following approaches:

Climate-informed Science Approach – The elevation and flood hazard area that result from using a climate-informed science approach that uses the best available, actionable hydrologic and hydraulic data and methods that integrate current and future changes in flooding based on climate science. This approach will also include an emphasis on whether the action is a critical action as one of the factors to be considered when conducting the analysis.

Freeboard Value Approach – The elevation and flood hazard area that result from using the freeboard value, reached by adding an additional 2 feet to the base flood elevation for non-critical actions and from adding an additional 3 feet to the base flood elevation for critical actions. [The term “critical action” shall mean any activity for which even a slight chance of flooding would be too great].

500-Year Elevation Approach - The area subject to flooding by the 0.2-100 percent-annual-chance flood.

Missouri River Basin1.3 million km2

Missouri River3,767 kmMax flow 21,000 m3/s

10 Million acre feet = 12,300 Million cubic meters

Precipitation March 2011

= 73,800 MM3

20,000 MM3

http://www.nwd.usace.army.mil/docs/MRIndependentReviewPanel.pdf

Dam Operation Review

• Operators must follow manuals• Operators must try to meet

needs; early release may harm future needs

• Operators must always protect structures

• Do not see how significant changes could be made without longer term forecasting

BUILDING STRONG®

Lessons Learned• The Dam System performed as designed. It serves (8) multiple

purposes and therefore cannot capably handle the most extreme of flood events

• Passing a major flood is expensive. Funds are needed to repair, rebuild, and reinvest in the infrastructure

• There is a lack of public understanding of how floods are handled and personal responsibilities in handling

• Flood risk can be mitigated beyond creating more space in the existing Dam System –designating floodways, establishing flood corridor easements - structural and non-structural

• Must organize around a common vision and with true purpose and acceptance of shared responsibility

Estes Park

“I’m stuck, I’m right in the middle of it, I can’t get out . . . about a half mile east of Drake on the highway. Get the cars out of the low area down below . . .”

144 People DEAD

Big Thompson 1976

2013 Big Thompson

Risk Communication

1. People generally underestimate risk

2. Residents misunderstand technical terms - “100-year flood”

3. There is mixed empirical evidence that increased risk perception translates into actions

4. There is considerable trust in structures in preventing risks

5. People will take the opinions and actions of friends, family, and neighbors into account in behavioral responses - social networks are often more important than official sources of information about risks and mitigation

6. Risk perception and behavioral responses are often influenced by experience with flooding.

7. Risk communication tends to focus on the technical but emotional and experiential aspects of disasters provide more impetus for undertaking behavioral change

Risk Communication Challenges

• Deliver at the local level,• Tailor to individual households, communities, and other

stakeholders• Deliver from a credible and trusted source• Ensure consistent, correct, and non-conflicting content• Encourage or motivate some behavior change• Account for the values of target audiences or

communities• Employ multi-modal networks• Provide repeat messaging

Risk Communication Principles

Local Delivery with High Level Support

Multi-Faceted Flood Maps

Lesson: 21st Century Users Want and Use More Information

Shelter

Water depth info

Evacuation way

JingwanTown

UN World Water Development Report 3

In Sum1. The Risks Associated with [Mountain] Floods

Are Increasing; Change (including Climate Change and Growth) Is a Major Influence

2. Understanding Risk and Developing Resilience through Multiple Means Mitigates These Growing Challenges

3. Governments and Society Must Both Be Fully Involved in Risk Communication and Resilience Development

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