How the city maintains good drainage

Drainage is one of those city services that is often out of sight, out of mind, yet critically important. Seeing the damage in other parts of the region from the recent storm, you might be wondering about Carlsbad’s drainage system and what we do to maintain it.

Usually when we share information about our storm drains it’s to remind you to keep contaminants from getting into the system. This is because water flows from streets, untreated, into our lagoons and ocean. Today I’ll tell you about the infrastructure itself.

Drainage infrastructure

Managing drainage in a city is both simple and complex. The simple part has to do with gravity.  We are part of a watershed, an area where water flows from inland, eventually making its way to the ocean through natural and man-made channels.

Once an area becomes populated, drainage needs to be engineered to move water away from areas where it could be a hazard to public safety and infrastructure, while also ensuring the environment is protected. Here are the main ways we do this:

Street gutters

What most people call curbs and gutters we call storm drains. Water is directed to these inlets from the street so it does not pool on the road or flood nearby homes and businesses.

Drainage pipes and channels

Drainage systems often utilize large pipes running under streets and open channels to collect and move excess water.

Pumps and flow control

To keep water headed in the right direction, it sometimes needs to be pumped. And, when there is too much flow, we might need to slow it down or adjust water levels through valves and other equipment.

Green infrastructure

The latest approach to drainage involves using special pavement that allows some water to seep into the ground. If you’ve visited the city’s Pine Park, you’ll notice the parking lot along Harding has a rougher surface than other lots. This is an example of permeable pavement, which is intended to reduce runoff.  The city plans and builds basins to hold and control water on both small and large scales. The goal is to handle and manage stormwater locally whenever possible.

Carlsbad’s drainage

For decades now, we have required new development to install high quality drainage infrastructure as a condition of approval.

Drainage systems were not included when some of Carlsbad’s older neighborhoods were built (some before we even were a city). Where drainage was built in the early days, the most common material was corrugated metal pipe, which only lasts around 50 years.

The city has been working to add drainage improvements where none existed and replace old pipes with newer, more durable materials. We have made significant progress, but it’s expensive, and it’s usually pretty disruptive to traffic, local homes and businesses. This is why we spread it out, completing several projects each year. We were even able to reprioritize some of this work during the COVID-19 pandemic so work in the Village could get completed while businesses were closed.

We still have projects underway and planned, but the city has already invested more than $50 million in storm drain infrastructure in older neighborhoods.

Regular maintenance

Even the best designed system needs constant attention to function well. This includes keeping channels clear of overgrown plants and other materials that could block water flow and gutters and inlets free from obstructions, especially when a storm is coming. 

Emergency response

Even with all this work, some low-lying areas can experience flooding during significant storms. That’s why the final key to managing drainage is to ensure we have crews in the field during storms. This includes staff who can remove fallen branches from the road and clear blocked drains. We even have a vactor truck, which is like a giant wet vac on wheels, to remove water if needed.

Residents can do their part by keeping an eye on gutters in their own neighborhoods and letting us know if something needs attention. You can use our Carlsbad app or, if it’s an emergency call our 25/7 emergency line at 442-339-2197.