Flooding

Jump to information about: flooding in Pendleton, what to do when there is a flooding event, sandbags, and additional resources.

 

The beautiful waterways in the City of Pendleton have many benefits, but they also come with risks, especially of flooding.

Watch this video for an overview of flood risk areas, the City of Pendleton’s response, and use of sandbags.

 

 

Background Information: Flooding in Pendleton

Multiple floodplains exist within the City of Pendleton. The floodplain is land that has been or may be covered by floodwater during the regional flood. The floodplain includes the floodway and floodfringe areas.

Image Source: FEMA, National Flood Insurance Program Guidebook, 2009

 

The City of Pendleton has three primary flood zones, each along a separate waterway:

  1. The Umatilla River
  2. McKay Creek
  3. Tutuilla Creek /Patawa Creek

Flooding events may affect one, multiple, or none of those higher-risk zones. 

Flooding can happen for a number of reasons, including snow melt and heavy rain. In the case of McKay Creek, water levels relate directly to the McKay Reservoir.

BOR Reservoir Levels

McKay Reservoir at 37% Capacity

McKay Reservoir at 91% Capacity
Image Source: Bureau of Reclaimation, Columbia-Pacific Northwest Region

The current capacity of the McKay Reservoir can be found on the Bureau of Reclamation’s website here. The City of Pendleton does monitor those water levels, as well as the release of water in times where the reservoir is in danger of overfilling. In those cases, the amount of water released from the reservoir into McKay Creek is increased.  This water is measured in cubic feet per second, or cfs. Depending on the amount of sediment and gravel in McKay Creek, the amount of cfs that could cause flood concerns changes.

The City will notify the public of increased flows through ORAlert and the City of Pendleton Facebook page.  For example, “The current inflow at McKay Reservoir is 1,100 cfs and slightly falling.  The BOR will keep the current outflow at 900 cfs at this time. The City and the BOR will continue to monitor and evaluate conditions and updates will be posted on Facebook.”

 

When there is a flood

In the event of a natural disaster, including flood or wildfire, the City of Pendleton will release information on the City website and social media pages.

Alerts with will be sent through ORAlert in the case of an order to:

  • Shelter in Place
  • Level 1 Evacuation
  • Level 2 Evacuation
  • Level 3 Evacuation

The following chart provides detailed descriptions of each alert type: 

Description of emergency response levels and messaging
Shelter in Place

City of Pendleton has issued an emergency "SHELTER-IN-PLACE" for the following areas:

[location]

PLEASE STAY INDOORS. DO NOT TRAVEL OR LEAVE YOUR HOME.

Flood Shelter-In-Place Helpful Information

Shelter-In-Place Tips 1-2 Story Building

Shelter-In-Place Tips Manufactured Home

Shelter-In-Place Tips Multi-Story Building

Level 1 Evacuation

A Level I Evacuation means “Be Ready” for potential evacuation

Residents should be aware of the danger that exists in their area, monitor this emergency service webpage and local media outlets for information & updates. 

This is the time for preparation and precautionary movement of persons with special needs, mobile property, and (under certain circumstances) pets and livestock.

If conditions worsen, emergency services personnel may contact you via an emergency notification system. 

Level 2 Evacuation

LEVEL II

A Level II Evacuation means “Be Set” to evacuate

YOU MUST PREPARE TO LEAVE AT A MOMENT’S NOTICE

This level indicates there is significant danger to your area, and residents should either voluntarily relocate to a shelter with family/friends outside of the affected area, or if choosing to remain, be ready to evacuate at a moment’s notice.

You should prepare now by packing necessary items and preparing your family, pets, and vehicle for potential departure.  Remember the 6- P’s:

A plan for persons in your family (including meeting place).

Personal items (including toiletries, food, water for 2-3 days and special personal possessions.)

Prescriptions: Have your full, current supply of prescriptions packed. 

Photographs (and other mementos) which cannot be replaced.

Pets (Have a plan in place and pets secured so frightened pets don’t escape fenced yards or kennels.)

Papers- Pack all important papers, including reference phone numbers, account numbers, etc. 

THIS MAY BE THE ONLY NOTICE THAT YOU RECEIVE

Emergency services cannot guarantee that they will be able to notify you if conditions rapidly deteriorate.  Area media services will be asked to broadcast periodic updates.

Level 3 Evacuation

LEVEL III

A Level III Evacuation means “GO”: evacuate now

LEAVE IMMEDIATELY!

Danger to your area is current or imminent, and you should evacuate immediately. 

You should take your family, pets, and necessary items including medications and important papers and evacuate now if you are in a Level III area.

Check in with your Red Cross Shelter (even if you don’t intend to stay there).  Check in with them and let them know where you will be in case your family is looking for you.

Drive safely and SLOWLY remaining aware of your surroundings as you leave. 

If you choose to ignore this advisement, you should understand that emergency services may not be available to assist you further. 

DO NOT delay leaving to gather any belongings or make efforts to protect your home.

THIS WILL BE THE LAST NOTICE THAT YOU RECEIVE

Entry to evacuated areas may be denied until conditions are safe.

Area radio stations have been asked to broadcast periodic updates. 

Sandbags

The use of sandbags is a simple, but effective, way to prevent or reduce floodwater damage.  Properly filled and spaced sandbags can act as a barrier to divert moving water around, instead of through buildings.  The most commonly used bags are untreated burlap sacks, available at feed or hardware stores.  Empty bags can be stockpiled for emergency use and will be serviceable for several years if properly stored, but filled bags of earth material will deteriorate quickly.  

In the event of a flood, the City of Pendleton will make sandbags and/or sandbag filling stations available.

To fill a sandbag:

Filling sandbags is a two-person operation.  

  1. One member of the team should place the empty bag on the ground with the top of the bag folded over and down to form a collar. This is held open, in a position where the other team member can empty a rounded shovel full of material into the bag. The person holding the sack should be standing with knees slightly flexed and head and face as far away from the action of the shovel as practical.  It is very important that both people wear gloves.wear gloves.  
  2. The second team member should carefully release a rounded shovel full of soil, into the top of the open bag.  
  3. The person shoveling should repeat Step 2 until the bag is between halfway and 2/3rds full.
  4. The team member holding the bag should then fold the top over and close the bag. 
Sandbag Placement

1.    Pre-wrap structure with thick plastic covering, secured with duct tape. The plastic covering should extend 4 feet up the wall and 4 feet out from the structure.
2.    Lay out a single layer of sandbags end-to-end along the base of the wall on top of the plastic
3.    Add a second layer of sandbags offset from the first
4.    Continue building until the wall is one foot higher than the expected crest of the water
 

 

Additional Resources

The Federal government has a great flood information resource at https://www.ready.gov/floods

US Corps of Engineers Flood Fight Manual at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/3578 

Bureau of Reclamation levels at https://www.usbr.gov/pn/hydromet/umatilla/umatea.html

Umatilla County Flood Hazard page at https://umatillacounty.gov/departments/community-development/planning-division/flood-hazard 

Umatilla County Soil & Water Conservation District Flooding Projects Page at http://umatillacountyswcd.com/resources/floodingprojecttracker.html