A familiar frustration
A street is repaved with fresh asphalt and smooth lines. A few months later, a crew arrives, cuts a trench across it and patches the scar. Residents reasonably ask why nobody planned better. The usual answer is that nobody was in charge of the whole picture. Paving, water, sewer, gas, power and communications are often managed by separate organizations with separate budgets and calendars, and each acts when its own needs say so.
Dig-once policies are a set of rules and habits meant to change that. The goal is simple even if the execution is not: when a street has to be opened, do as much of the necessary underground work as possible at the same time.
Why repeated digging costs so much
Opening a street is costly in several ways, and the costs recur with each cut.
- Direct costs. Excavating, shoring, hauling soil, backfilling and restoring the surface are labor- and equipment-intensive.
- Pavement damage. A trench weakens the surrounding pavement. Patches often fail sooner than undisturbed surface, and repeated cuts accelerate decline.
- Disruption. Lane closures, noise, dust, parking loss and blocked driveways affect residents and businesses each time. This is part of the wider topic of construction disruption.
- Risk. Every excavation carries the chance of hitting another buried line.
- Trees and surface features. Digging can damage roots and require removing and replacing street elements.
Because much of the cost is in opening and closing the trench rather than the pipe or cable itself, adding a second service while a trench is already open is typically much cheaper than digging separately later. The exact savings vary by project and should not be assumed.
What dig-once looks like
Policies differ, but several tools appear again and again.
Shared project calendars. Cities keep a list of planned street projects, often several years ahead, and ask utilities to review and add their plans. If a street is scheduled for reconstruction, utilities learn early and can replace aging lines first.
Notification and coordination meetings. Regular meetings where agencies and companies compare plans can prevent conflicts. It sounds basic, but it is often the step that is missing.
Moratoriums on new cuts. After a street is repaved or reconstructed, the city may restrict new excavations for a set period, often several years. Utilities then have a strong reason to finish their work before the paving. Exceptions are made for emergencies.
Permit review. When someone applies to dig, staff can check whether other work is nearby, and may require or encourage the applicant to coordinate.
Joint trenching and shared conduit. Multiple providers place their lines in one trench or use ducts that others can rent. This is closely related to the practice of installing fiber conduits during road projects.
Better surface restoration standards. Requiring trenches to be repaired to a higher standard, such as full-width restoration, reduces long-term damage and makes cuts less attractive.
Where it gets difficult
Coordination sounds obviously sensible, and yet it is hard in practice, for reasons that are mostly about timing and money rather than ill will.
- Different schedules. A water utility may have funded pipe replacement for next year while the road project is scheduled in three. Neither can easily move.
- Different budgets. A city’s paving fund and a utility’s rates are separate pools. Money cannot always be shifted to speed a project up, and a utility may be unwilling to replace a pipe that still works just because the road above is being rebuilt.
- Private companies’ plans. Commercial service providers decide on expansions based on demand, which a city cannot always predict.
- Emergencies. Main breaks and outages cannot wait for the calendar.
- Uncertain futures. Installing spare capacity costs money now for a benefit that may or may not arrive. Choosing how much to install is a judgment call.
- Legal limits. Rules about who may require what from utilities vary widely by country, region and type of utility, and some can limit what a city can mandate.
Trade-offs worth noting
Bundling work can make a single project bigger, longer and more disruptive for a time, in exchange for fewer disruptions later. Businesses on the street may prefer a short, sharp project, while others dislike a prolonged one. Coordinated projects can also be more complicated to manage, with more parties and more chances for delay.
There is also a question of what to replace. Digging up a street to install a new main when the old one still has years of life may be wasteful, while leaving it risks a break soon after. Condition data from asset management helps make this call. Without good records, coordination decisions rely on guesses.
Making it work
Experience suggests a few practical habits that improve results, though none guarantees success: keep a single, public, regularly updated list of planned work; set a clear window for utilities to respond before a street is finished; give staff the authority to say no to avoidable cuts; and track how many openings happen in newly paved streets to learn whether the system is working.
For a small project, dig-once can simply mean asking a few questions before the contractor starts: who else needs this street, and what could we put in the ground now so we do not need to return?