Photo of the May 20, 2013, tornado as it approached the Draper WTP. Provided by Jim Crawford, City of
Oklahoma City Draper WTP Superintendent.
Photo of the May 20, 2013, tornado breaking up before it reached the Draper WTP. Provided by Jim
Crawford, City of Oklahoma City Draper WTP Superintendent.
Pray for the Best, Plan for the Worst
April showers bring May flowers, but something very different threatens us from the skies above.
Tornadoes. In the Southwest Section, the spring season brings tornadoes – and plenty of them. From
1991 to 2010, according to the National Climatic Data
Center, the annual average number of tornadoes for
Louisiana is 39, Arkansas is 45, and Oklahoma is 62.
Even without a direct hit to a water or wastewater
plant, operations can be affected.
Minimal or No Water Production. A power outage
will slow or cease the ability to receive supply, treat
and/or convey treated water. Even with the ability
to convey minimum flows, areas such as fire
protection, hospitals and emergency uses, and
home use can be greatly impacted.
Customer Confidence. Notifying the public that they must only use water for critical needs is a
tough message to deliver. Once customer confidence is affected, trust is difficult to regain.
Revenues. In the worst of cases, as with Moore, Oklahoma, in the 2013 tornado season, a loss of
1,200 water customers resulted in inadequate revenues to cover expenses.
Infrastructure. Should elevated tanks in the distribution system or the treatment plant itself be in
the path of the tornado, repairing or rebuilding may take months, and in some cases, years.
Environmental. For facilities housing chlorine gas or other hazardous chemicals, a release or a spill
can trigger another disaster.
In last year’s example, the May 19 and May 20 tornadoes passing through Central Oklahoma caused
damage to power supplies serving Oklahoma City’s Draper Water Treatment Plant (WTP). Draper WTP
was down for 21 hours, although the WTP sustained no direct damage. In this unusual situation, both of
the redundant electrical power feeds were down. This summary highlights their experience:



Draper WTP, located on the southeast side of Oklahoma City, has two electrical feeds for
redundancy and one diesel high service pump capable of 15 million gallons per day (mgd).
On May 19, a tornado takes out Draper WTP’s south electrical service feed. Draper WTP
continues to run on the north service feed while Oklahoma Gas & Electric (OG&E) begins
repairing the south service.
On the next day, May 20, after passing through Moore, destroying 1,200 homes and damaging
many more, a monster tornado travels directly toward the Draper WTP – and fortunately, leaves
the ground before causing direct damage. At 3:30 p.m., this tornado takes out Draper WTP’s





north electrical service feed – leaving the WTP with no electrical service. At the time, the plant
had been sending 64.5 mgd to distribution.
With both electrical services down, Draper WTP starts up the 15 mgd diesel pump. The pump
runs for about 4 hours until 10-feet of finished water (7.5 MG) remains in the clearwell. This
remaining volume is needed for WTP startup and must be reserved. With electrical service
completely out, the treatment processes are non-operational.
Hefner WTP, Oklahoma City’s second largest treatment plant, increases production as pressures
in the distribution system begin to fall.
Through a pre-arranged contract, utility staff place a purchase order for an emergency diesel
generator and a compatible transformer to be delivered. With the situation in Moore and
South Oklahoma City, the highways and most through-roads were impassible. The diesel
generator is eventually delivered that night; but without the transformer, it cannot be used.
Through a press release, the City of Oklahoma City requested that the public “turn off sprinkler
systems and postpone using washing appliances to help maintain water in the pipeline delivery
system.”
May 21, 12:54 p.m. OG&E crews working to repair the south service feed which was damaged
during the May 19 tornado are successful, and power is returned to Draper WTP. After startup,
the WTP ramped up to 75 mgd production.
One point to take away from the story is that even when the best plans are made, things can happen
differently than anticipated. Examples: 1) It is common for water or wastewater plants to have
redundant power feeds. It is uncommon for two consecutive days of tornadoes to take out both
services. 2) It is common for a plant to have on-call type contracts. It is uncommon for routes to be
impassible such that the deliveries cannot be made.
Are staff at your utility prepared for tornado season? Undoubtedly, most in our Southwest Section have
lived through a tornado or the threat of a tornado. Sheltering plans and shelter locations are typically
known by all and the process for staying weather aware is a normal part of our routine during tornado
season. We are experts, per se. After all, we get plenty of practice.
What about after the tornado passes and the utility system has been impacted? If you are without a
response and recovery plan, take time this month to make a plan. Consider these actions after the
tornado has passed:
1. When it is safe to leave shelter, personnel should report to their workplaces and accountability
for all personnel should be made. At all times, downed power lines should be avoided.
2. If power is down, notify the power company, determine the impact of the outage and determine
alternatives such as backup generators or an emergency water connection with a nearby city.
3. If heavy damage was sustained, establish an Emergency Center which will include staff to
maintain communications with all involved parties – municipality staff (operations,
maintenance, engineering, etc.), emergency response staff, vendors, deliveries, public relations,
etc.
4. Determine operability of the facility and evaluate what damage has been sustained. If systems
are operable, continue to monitor. If systems are damaged or inoperable, notify customers
immediately and begin planning for alternative and prioritized service.
5. Prioritize repairs and recovery of systems and buildings. Contact and coordinate with vendors
for removal of debris and/or clearing ingress and egress to impacted sites.
6. Contact families of employees to keep them informed of their family member’s status and help
employees maintain contact with their family. Having current and valid employee and family
contact information before an emergency happens is crucial.
7. Coordinate response and recovery plans with operations, maintenance, and engineering.
8. Maintain log of actions including times actions were initiated and completed.
Granted, being born and raised “around these parts” will give a person an innate ability to perform
backyard meteorology and identify tornado weather. However, we cannot prevent a tornado and
having a team which is aware and prepared for the response and recovery stages is the best weapon
against disaster.
Oklahoma City now has an ongoing project to install emergency transformers so that once an
emergency diesel generator is delivered, the WTP will be able to run on that backup power supply.
When Monte Hannon, Operations Manager for the City of Oklahoma City, was asked about the lessons
learned last year after going through the May 19th and May 20th tornadoes, he offered the following:





Step-up transformers are required to increase the voltage from 480V (common with most
generators) to 4160V to 12KV (which are common loop voltages in many large plants). Large
step-up transformers are more difficult to locate and rent than generators. Oklahoma City has
purchased and installed stand-by transformers at the large plants. Delivery time on these
transformers can be six months for new ones and slightly less for rebuilt. Sometimes it is less
expensive and quicker to purchase two smaller transformers than one large one.
Backup generation capacity to run the entire plant is typically not needed. Possibly half capacity
will be enough in an emergency situation as consumption will be less during an area-wide
emergency and customers tend to understand the need to conserve.
It takes several days for Oklahoma City staff to bring an offline plant back into service and only a
few hours to increase flows for an online plant. Having all plants operational before tornado
season begins is advisable – even if they are only “idling.”
Have Meals-Ready-to-Eat (MREs) available for plant staff during emergencies so they can keep
going during the initial emergency. Otherwise, staff will need to leave to get meals or food
should be brought in so that staff stay energized and focused.
Plan multiple routes to your critical facilities and communicate these with your contractors.
Their GPS will plot the closest route which may not be open. Turning a semi-truck around on a
blocked or dead-end, two-lane country road is extremely difficult. Drive the roads before the
semi-trucks arrive to ensure they are passable – and communicate this information to the
delivery service.

Even though a Utility has planned and thought through an emergency, the emergency never
cooperates and some part of the plan will fail. Be flexible and adjust quickly.
Candy Staring, Oklahoma Trustee, Southwest Section