Shoring Up: Critical Steps for Substation Flood Control

Critical Steps for Substation Flood Control

Flood hardening. Even utilities that are not in a coastal region or high-risk flood zone should take it seriously. According to the IEEE Power & Energy Society, recent “superstorms” have increased pressure on utilities and governmental agencies to harden critical infrastructure for improved grid system reliability during major storm events.1 Ground zero for flood hardening is substations, which can make or break a utility’s flood response effort.

In the event of flooding, substations may lose HVAC systems, AC station service, communications or DC battery systems. They may experience water damage to protection, automation and control equipment; damage to high-voltage equipment from flooding in switchyard; de-energization of the entire substation; or even fire or catastrophic loss. The industry standard for substation site design is to avoid significant impacts from flooding at the 100-Year Flood Elevation, plus one foot. But, even in some historically low-risk areas, that standard may not be enough. Not anymore.

IEEE Power & Energy Society recommends the following steps to help ensure substation flood safety:

  1. Determine the scope of flood mitigation for each substation. First, identify critical substations with vulnerability to storm surge or that are located in high-risk flood zones. Then, for every substation, evaluate the risk of loss for specific equipment or systems. Some stations in historically low-risk areas may require high mitigation planning simply because the consequence of a flood within that area or with certain equipment is particularly detrimental.
  2. Install flood monitoring devices. Float switches installed at various elevations throughout a substation, which can be hardwired into the station’s SCADA system, can notify operators when flooding first occurs and as flooding reaches critical stages.
  3. Elevate substations and equipment. Modular equipment solutions can be raised off the ground using elevated foundations, platforms or stilts. For high-risk areas, entire substations may need to either be strategically elevated or even moved to a safer location.1

The Environmental Protection Agency (EPA) offers flood preparation checklists for utilities. Many of these resources, which are accessible at www.epa.gov/waterriskassessment, are specifically for water and wastewater substations and their service areas, but are useful for electrical substations as well. As an example, it’s important to assess power, energy and fuel supplies. To do so, take these EPA recommendations under consideration:

  • Evaluate the condition of electrical panels to accept generators; inspect connections and switches.
  • Document the power requirements of the facility, which can be accomplished by placing a request with the U.S. Army Corps of Engineers or using the group’s online Emergency Power Facility Assessment Tool (EPFAT).
  • Confirm and document the generator connection type, capacity load and fuel consumption. Test regularly, exercise under load and service backup generators.
  • Contact fuel vendors and inform them of estimated fuel volumes needed if utility is impacted.
  • If it’s a water utility, collaborate with your local power provider and EOC to ensure that it is on the critical facilities list for priority electrical power restoration, generators and emergency fuel.2

Don’t wait until the skies open up to prepare for flooding. With the dawn of the “superstorm” era, no location is safe from the potentially catastrophic effects of rising waters.


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Sources

1. http://www.ieee-pes.org/presentations/td2014/td2014p-000564.pdf

2. http://www.epa.gov/sites/production/files/2015-06/documents/flooding.pdf