Boulder Flood September 11, 2013

Statistics Boulder County

Deaths: 4

Unaccounted for: 0

Homes destroyed: 346

Homes damaged: 557

Structures impacted by flooding 10,400

Commercial properties destroyed: 3

Commercial properties damaged: 33

People evacuated by air: 1,102

People evacuated by road: 707

County Road damage: approx. 150 miles

Stats continually changing:

Boulder County damage - $200 million

Longmont - $125 million

Lyons - $43 million ($1million annual

budget)

City of Boulder - $17 million

Colorado Total - $2 billion in losses

Homes and Residences - $900 million

Flooding results

25 Year Event

Boulder Creek in City of Boulder 5,000 cfs.

500 Year Event

Lyons St Vrain River over 25,000 cfs.

1000 Year Event

Multi County Region Event

Pre-Planning • Historical Incidents date back

to 1860 • 20+ years: Flood Insurance

Program, public messaging, mitigation projects, training and exercises.

• Incident Action Plan from Fourmile Fire, 9/6/2010

• Higher flood risk from burn scar.

Additional Planning & Training

Emergency Plans

Evacuation Plans

COOP in all County Depts and many City Depts

MAC group – monthly

Pre flood season presentations

Annual table tops, exercises

Meet regularly with police and fire and other

first responders to support them

Pre Flood Planning

Assumptions…. We were planning for a flood in Boulder Creek or

one or two drainages. Every drainage in the county flooded.

Access problems would be local to the area. Every highway and road was impacted.

Evacuations and Sheltering in unaffected areas could handle the surge. All routes to shelters closed, opened shelters had

to be closed, new ones found, residents moved, and new shelters were not in sheltering plan.

Flood Predictions

Actual Predicted

EOC Abilities

Relationships with NWS, UDFCD

Flood creek computer modeling

Matrix of rain/time/cfs/risk

Flood plain mapping / alert zones

Stream gauges

Rain gauges

GR3 radar

Cameras on critical areas

EOC Weather Monitoring

July 1, 12, 13, 14, 15, 18, 19, 24, 25, 29

August 1, 3, 8, 12, 13

Sept. 9, 10, 11

UDFCD and NWS issued 100’s of message

products from July to September, a very

busy monsoon season.

Weather: Monday the 9th

M2 Flash Flood watch 12:38pm

M1 Low Impact Flooding 6:27pm

M1 Low Impact Flooding update 7:33pm

NWS calling us directly that this could be a

bad weather week.

Weather: Tuesday the 10th

M1 Street Flooding potential 12:14pm

EOC staff still monitoring weather

conditions

NWS Concerns

“The Storm is moving upslope and stalling,

the rain has intensified, the ground is highly

saturated and your Dew Point is 67

degrees.”

Our worse case scenario is a dew point over 55

degrees and an upslope storm (The dew point

was over 55 from Sept. 9 to 14).

Weather: Wednesday the 11th M1 Street Flooding potential 9:18am M1 issued by UDFCD 11:17am

EOC staff responds to monitor weather 11:30am Weather Spotters Activated 11:55am

EOC elevated to functional activation and severe weather protocol implemented 2:30pm

M1 Low Impact Flooding 4:16pm

M3 Flash Flood warning 6:50 pm

M3 Flash Flood warning update 7:09 pm

EOC elevated to core activation 8:01pm M3 Flash Flood warning update 8:07 pm

M3 Flash Flood warning update 10:06 pm

M3 Flash Flood warning update 11:38pm (15 more M3’s through Sunday, Sept. 15)

Monitoring

EOC in direct contact with:

Sheriff’s Office

Boulder Police and Fire Departments

Colorado State Patrol

Rocky Mountain FPD

Four Mile FPD

Boulder Mountain FPD

National Weather Service

Urban Drainage Flood Control District

NWS Concerns

Storm is moving upslope and stalling

Rain has intensified

Ground is highly saturated

Dew Point 67 degrees

A dew point over 55 degrees and an

upslope storm is our worse case scenario.

(The dew point was over 55 from Sept. 9

to 14)

First Reports of Flooding

Erie PD reports water over Erie Parkway

and other streets, Everbridge alert at 1923

Gregory Canyon roadway debris

Lookout Rd from 79 to 95th flooded

Culverts overflowing county wide

City of Boulder: 17/18th on the Hill; Baseline

and Foothills; 9th and Alpine

Arapahoe and E County line flooded

CU Students - Youtube

Public Warnings 2321 Four Mile Canyon – climb to safety

2341 Anne U White - climb to safety

0025 City Of Boulder - climb to safety at mouth of the canyon

0036 Jamestown - seek higher ground

0107 Longmont Dam Rd - seek higher ground

0110 South St Vrain – seek higher ground

0135 Jamestown – seek higher ground

0217 Lyons – seek higher ground

A Blur of Several Hours

Four Mile burn gets 4 inches in 6 hours

Boulder Creek at 2600 cfs and 4000 expected

Most drainages are beginning to flood

Most roads are being impacted by flooding

Mudslides / Landslides

Abandoned vehicles

Structures impacted or lost

Rainfall Map

Fatalities

Jamestown: First reported fatality as a

result of a mudslide causing a house

collapse after flooding on James Creek.

Two Mile Creek: Two fatalities. Two Mile

Creek was a tiny creek with insignificant

flow – not even on our flood risk radar.

Lyons: Elderly man caught in a vehicle in

the North St. Vrain River. Found deceased

a week later.

Emergency Operations Center

EOC: 24 hour operation for 8 days

EOC: continued 16-18 hour operations for 6 more days

490 different users of WebEOC

422 resource orders processed, most with multiple resources

Roughly 100 people working around the clock in the EOC.

EOC Briefing

EOC Briefing

EOC Operations

EOC Operations

The Rescue Operations: By Land, By River , By Air

Search & Rescue

Finally Safe

Damages

FEMA project specialist:

“I have not seen this before -

the house is gone;

the foundation is gone;

the land the foundation was on is gone.

All that’s left is a ravine”

City of Boulder

Incident Command Post

Security, and Re-Entry

PIOs, Elected Officials & Dignitaries

Shelters

Disaster Assistance Centers

FEMA Applicant Briefing

Debris

Recovery

• Stabilization

• Short, Medium, and

Long Term Recovery

• Unmet Needs

• FEMA: Individual

Assistance

• FEMA: Public Assistance

Future issues: Spring Runoff from Snow Melt

Ice Dams

Unstable Hillsides

Debris in the Creeks

Questions?

Damages: Lyons

Damages: Longmont

Damages

Damages: Canyon Roads

Damages

Damages

Damages:

Jamestown

Damages: Jamestown

Lefthand Creek

Damages:

Salina

Damages: Salina

Any last questions?