DHSEM Update: May 26, 2015



Read this edition of the DHSEM Update dated May 26, 2015.


Colorado Daily Status Report May 26, 2015

Alerts/Warnings:
State Emergency Operations Center (SEOC) Status:
Day to Day
Current Disasters/Large Incidents:
The Colorado Division of Homeland Security and Emergency Management (DHSEM) staff is monitoring statewide weather conditions and impacts.
DHSEM staff remain in direct contact with local county emergency operations centers, emergency managers and emergency responders. 

Dam Safety: Are you prepared for a dam emergency?



Information provided by the Colorado Department of Natural Resources' Dam Safety Branch.

If you live in Colorado you are aware of the above average precipitation we have had and the saturated conditions of our ground in much of the state. Rivers are running high as is typical for this time of year, and the added moisture is making flooding more likely than ever. These conditions put added pressure on dams. The extra runoff can make streams run that normally don’t and fill small ponds and reservoirs that are typically dry. Below are some facts about dams and preparations and actions that community members can take to keep themselves and their neighbors out of harm’s way in the event of a dam emergency in their area.

Facts

  • The larger dams you see in your area with large concrete structures and wide open spillways were designed for extreme amounts of rain. Those structures were designed specifically handle and safely pass the volumes of rain and moisture we are currently experiencing.
  • Even during normal operations, some spillway flows may be damaging and hazardous to the downstream channel and care should be taken around spillways discharging to those channels
  • Smaller neighborhood dams, farm ponds, livestock ponds and erosion control ponds are less hazardous due to their small size, but can still be dangerous if someone finds themselves in the wrong place at the wrong time.
  • Water flowing from spillways, outlet works or even over a dam generally follow established and defined stream channels or drainage paths.
  • More useful information about dams and their safe operation can be found in the Dam Safety Manual provided by the Colorado Dam Safety Branch at: http://water.state.co.us/DWRIPub/Documents/DS_Manual.pdf
  • Or on our dam safety website at: http://www.water.state.co.us/damsafety/dams.asp:

Preparation

  • Now is a great time to make yourself aware of your surroundings and the likely numerous dams in your area. Take notice of reservoirs in your area and areas of normal travel and recreation.
  • Take notice of the stream channels and drainage ways that affect you every day.
  • Notice low areas and channels and find the highest surrounding ground nearest to them. Memorize where those high places are
  • Seek out sources of current weather information and stay tuned to those sources when conditions dictate.

Actions

  • In the event of high stream flows, sheet flows down streets or flows in ditches, always seek the higher ground 
  • Never travel in or cross a flooded area or a path of moving water on foot or in a vehicle, Turn around, don’t drown! 
  • Pay attention to weather and weather alerts in your area
Photo: Normal safe operation of a dam with water flowing past the dam through the defined spillway structure.
Normal safe operation of a dam with water flowing past the dam through the defined spillway structure.

Photo: An earthen dam being overtopped.  This is an emergency condition and should be reported and treated with extreme caution.
An earthen dam being overtopped.  This is an emergency condition and should be reported and treated with extreme caution.

Colorado Daily Status Report May 22, 2015

Alerts/Warnings:
State Emergency Operations Center (SEOC) Status:
Day to Day
Current Disasters/Large Incidents:
The Colorado Division of Homeland Security and Emergency Management (DHSEM) staff is monitoring statewide weather conditions and impacts.
DHSEM staff remain in direct contact with local county emergency operations centers, emergency managers and emergency responders. 

Dam Owner Safety Tips and Recommendations Due to Current Weather



Information provided by the Colorado Department of Natural Resources' Dam Safety Branch.

If you live in Colorado you are aware of the above average precipitation we have had and the saturated conditions of our ground in much of the state. Rivers are running high as is typical for this time of year, and the added moisture is making flooding more likely than ever. These conditions put added pressure on dams. The extra runoff can make streams run that normally don’t and fill small ponds and reservoirs that are typically dry. The Dam Safety Branch of the Colorado Division of Water Resources would like to remind owners of dams a few simple things they can do to prepare for this higher than usual runoff, defensive actions they can take to prevent negative impacts and notifications they can make in the event of an emergency situation.

Preparation

  • If you have a low level outlet pipe, open it and lower your reservoir level before additional runoff occurs
  • Ensure spillways are clear of debris and are open and functioning as fully as possible
  • More closely monitor conditions on your dam. This will create a baseline of the conditions now that can then be compared to if and when the reservoir fills to the level of the spillway.
  • As the reservoir fills, continue monitor conditions to ensure spillways stay clear and open, outlets remain open and functioning, and that conditions on the dam are not changing relative to your baseline conditions
  • Talk with your downstream neighbors. Inform them of the higher than usual water levels and what you are doing to keep your dam and them safe.
  • Have names and phone numbers available so you can contact your local emergency manager, local dam safety engineer and downstream neighbors in the event that conditions at your dam change for the worse

Defensive Actions

  • A list of possible defensive actions is described in some detail in Chapter 15 - Emergency Plans, of the Dam Safety Manual, which is available online at: http://water.state.co.us/DWRIPub/Documents/DS_Manual.pdf
  • In general defensive actions include the following (see Dam Safety Manual for details)
    • Clearing clogged spillways and outlets
    • Opening outlets as wide as possible
    • Protect dam crests with sand bags or plastic tarps or sheeting (visqueen)
    • Stockpiling granular materials near the dam to use in case of unusual seepage or settlement
  • If time allows contact a licensed engineer for help with developing problems
  • If time allows contact an excavating contractor with heavy equipment and access to repair materials
  • Dam Safety Engineers with the Colorado Division of Water Resources are located strategically throughout the state and can be called with questions related to dams; Their contact information can be found at: http://water.state.co.us/SurfaceWater/DamSafety/Documents/CO_DAM_SAFETY_brochure.pdf

Notifications

  • Each county has an emergency manager who is an unequaled resource in an emergency. A list of emergency managers by county can be found at the following website:  http://www.coemergency.com/p/local-info-sources.html
  • Chapter 15 describes some common sense steps for emergency notification of downstream residents. In general, there are two cases:
    • In more populated areas the county sheriff may take the lead on notifications, if they themselves are made aware,
    • In rural areas it may be more expedient for the dam owner to reach out to their neighbors. Planning for either case may be the best way to save lives

Dam Owner Liability

Lastly, we need to remind owners of dams that if you have a dam on your property, you are responsible for the safety of the dam and are liable for damage if the dam fails.
Plastic  sheeting placed on a dam crest and downstream slope to protect the dam from saturation and erosion due to overtopping
Plastic  sheeting placed on a dam crest and downstream slope to protect the dam from saturation and erosion due to overtopping

Filter fabric and then granular pea gravel placed over an area on the downstream slope of a dam to control excessive or unusual seepage
Filter fabric and then granular pea gravel placed over an area on the downstream slope of a dam to control excessive or unusual seepage

Sand bags in place on a dam crest to prevent overtopping
Sand bags in place on a dam crest to prevent overtopping