Really piling up

May 4, 2015

Denver pulls in all resources to handle extreme events

Operations workers know that the only constant in their world is change.

Most take pride in the fact they can react and adjust to changing conditions, changing requirements and changing response. Occasionally Mother Nature will throw a curveball, and standard response tactics are no longer effective. Advance planning for those rare occurrences is necessary for operational work groups to continue and succeed in their mission.

Every agency responsible for snow response, from the smallest community to state DOTs, will feel the effects of a winter storm that stretches resources to the breaking point (Denver—Blizzardpalooza 2006-07; Seattle—2008; Washington, D.C.—Snowmaggedon 2010). Each of these events, and others, showed that existing response plans were lacking. There is an old saying, “Fool me once, shame on you; fool me twice, shame on me.” Out of these events new plans and procedures were developed to deal with the next major event.

Seven weeks too long

In 2007, managers in Denver learned the current plan for major storms was insufficient for an event that did not fit the historical pattern of snowstorms greater than 12 in. Large storms are common in spring, extremely rare in midwinter. Denver’s snow plan prior to Blizzardpalooza was to plow local streets after arterials were cleared for large snowstorms. This works well with spring storms when warm weather follows to aid in clearing streets. A set of storms in the holiday period of 2006-07 resulted in 8 in. of compacted snow and ice blanketing all local streets, which took seven weeks to clear. The need hit us like a slush ball in the forehead.

The goal was simple. Few properties are more than three blocks from a plowed route. Providing an accessible route to those plowed routes concurrently would allow the public to move about the city and maintain a sense of normalcy during extreme weather events. This could not be done with existing plowing resources; a stand-alone operation was needed to achieve this goal. The standard that was set was to clear the center 1⁄3 of each local street in the city with a minimum of one pass in each direction during each 12-hour shift. The standard for the large plows on the arterials is bare pavement. This was not considered achievable on the local streets—3-in. accumulation and minimal rutting is the local standard.

Denver has approximately 2,100 centerline miles of streets. Standard plow operations using tandem mounted plows address 700 miles, leaving 1,400 miles that would be part of the new residential plowing program. During a 12-hour shift, a plow will have its blade down and pushing snow for 2⁄3 of the shift at best. Pretrip and post-trip equipment inspections, fueling, traffic snarls, breakdowns, travel to the designated plow sector and allowed breaks use up a significant portion of a shift. Using an effective plow speed of 5-10 mph, it was determined that each truck should be assigned no more than 25 lane-miles. Simple math showed 110 plows were needed for this program. 

Denver follows the ICS/NIMS model for reporting structure, and 22 sectors were created each with five plows and a supervisor, four to five sectors per zone with a superintendent each, and a shift manager with overall management. With supervisors and support personnel, 250 people were needed to staff two 12-hour shifts.  

Calling on everyone

By mid-2007, Denver managers knew the need, set a goal and determined what was necessary to achieve the goal. Then the question became how to implement it.

 The city, with the assistance of other agencies, could assemble an impressive fleet of light-duty trucks that could be equipped with plows, but it was still well short of the need. Staffing was a bigger issue. The city could take two approaches: privatize the work using contractors, or provide the service in-house. Either process has pluses and minuses. In-house staffing requires closing many public works agencies to normal business to staff plows during these infrequent events. On the plus side, there is better flexibility using an in-house staff. Contractors like stability, and a response based on a once-every-several-years scenario makes it difficult to keep quality contractors available on a moment’s notice. They do, however, allow for the continued operation of other public works agencies.  

The city of Denver’s public works department has a staff of 1,100 people. Removing critical functions from plowing consideration (solid waste, CDL plow drivers, fleet and management) brought the available staff to a level that did not allow for sufficient drivers to man 110 plows on two shifts. Denver Parks and Recreation has plows that they use to clear bike paths across the city. Enlisting their help supplied 30 plows. We also determined that limited contracted support of 25 plows could further reduce the in-house staff needs allowing for critical agency duties to stay operational and provide a backup if needed. This plan reduced the equipment shortage to roughly 30 plows. The city solicited bids and purchased 1-ton, non-CDL pickups to augment the previously available equipment.  

A total of 110 plows could then be deployed in two 12-hour shifts with a mix of 75% in-house and 25% contracted services. Staff was pulled from many different public works groups (right-of-way enforcement, permits, inspection, survey, engineering, street maintenance, non-CDL staff, wastewater and traffic engineering), all needing no more than a standard Class R driver’s license. Drivers are voluntary in as much as their desire to be part of the program; however, once they are part of the team, reporting to an event is mandatory if deployment is ordered. Salaried staff is paid straight-time overtime over 40 hours; hourly staff receives time and a half.

Training was, and continues to be, a critical component to the program. Many of the plow drivers are field personnel; many are office staff. Parks staff is familiar with plowing, but the public works staff is not. Driving with a 1,000-lb plow blade in heavy snow when there is marginal visibility in the dark is out of the comfort zone of most people.

Classes are held annually to refresh each driver with the function of the plow, and they all are required to navigate a coned course to refresh the actual feel of driving with a plow. Other topics covered in the annual training are vehicle inspections, accident-reporting procedures, radio protocol and public interaction.

Public education is a critical component to the program. Citizens are used to seeing major routes plowed to bare pavement curb to curb on a continual basis for all winter events. The residential plowing program does not meet that same standard for both when they are deployed and the standard they meet. The cost of deploying light plows is large—$150,000 every 24 hours. Multiple deployments for relatively minor storms cannot be sustained with existing budget constraints. 

Triggers were set to help ensure deployment would occur only for extraordinary circumstances: A prediction of 12 in. of snow in one event and extended cold temperatures that would contribute to the development of serious ice ruts. Historically, that combination occurs in Denver once every couple of years. Using media releases, website, social media, public meetings and other forums, the public and elected officials are continually provided with information on how and when the program operates.

Striking the storm

Denver deployed the program twice in the two years following inception for storms that did not reach the trigger points but provided opportunities to test the concept.  

The first real deployment occurred with a storm that struck Denver Feb. 2-4, 2012. The prediction of the storm was for 10-20 in. starting on Thursday afternoon on Feb. 2 extending to Saturday morning. The first shift was brought in midnight Thursday (Friday morning). Continuous operations were maintained Friday and Saturday. The results were a rousing success. The official snow total at Denver International Airport east of town was 15 in., but most of the city received 18-20 in. With the exception of a few cul-de-sacs, all streets were passable throughout the storm, and crews never were caught in catch-up mode. 

Staying ahead of the accumulation is allowing us to consider if we can release the Parks trucks from the program so they can stay ahead of their obligation to clear parking lots and paths in city parks.

With proper advance planning and attention to detail, agencies of all sizes can develop a parallel program to deal with extreme weather events and keep their citizens mobile. The lessons Denver and others can learn from this can be applied to other unexpected or rare occurrences. The application of ICS/NIMS structure and thoughtful organization while not under the stress of an actual event can reap the benefit of a safe and successful operation. WM

Sponsored Recommendations

Concrete Protection That’s Easy on the Environment and Tough to Beat

PoreShield's concrete penetration capabilities go just as deep as our American roots. PoreShield is a plant-based, eco-friendly alternative to solvent-based concrete sealers.

Proven Concrete Protection That’s Safe & Sustainable

Real-life DOT field tests and university researchers have found that PoreShieldTM lasts for 10+ years and extends the life of concrete.

Revolutionizing Concrete Protection - A Sustainable Solution for Lasting Durability

The concrete at the Indiana State Fairgrounds & Event Center is subject to several potential sources of damage including livestock biowaste, food/beverage waste, and freeze/thaw...

The Future of Concrete Preservation

PoreShield is a cost-effective, nontoxic alternative to traditional concrete sealers. It works differently, absorbing deep into the concrete pores to block damage from salt ions...