Building resiliency and adaptability into the nation’s infrastructure: A conversation with Steve Moddemeyer

According to Steve Moddemeyer, a former senior advisor to Seattle Public Utilities and the city’s Department of Planning and Development, new paradigm shifts in government service delivery and infrastructure management are leading more officials to consider sustainable solutions. In a conversation with Mr. Moddemeyer, he told CivSource that governments can no longer afford to approach 21st Century infrastructure building based on 19th Century thinking.

Before joining the Seattle-based architectural firm, CollinsWoerman, Steve Moddemeyer worked for Seattle Public Utilities and later the Department of Planning and Development to help them develop a new segment of their land use code for landscaping – one that is based on sustainability, resiliency and adaptability. At Seattle DPD, Moddemeyer authored a landscape requirement called Green Factor, which is an expanding pilot project in the city. While the average person may think the requirements are purely aesthetic or part of an earth-loving bureaucratic agenda, it is part of a design and governance approach that is much more dramatic.

“The infrastructure model that cities use now is based on 19th Century thinking,” Mr. Moddemeyer told CivSource in an interview. “And we really have a whole new world – with population growth, energy constraints and resource constraints. It’s imperative that utilities and cities start reimagining how they deliver their services, in a way that expects energy to be expensive, that minimizes environmental footprint and that’s adaptable and resilient.”

The City of Seattle annually allocates $650 million for capital spending to repair or improve infrastructure. One area of particular interest to Mr. Moddemeyer was Seattle Public Utility’s combined sewer overflow system. He said in the late 1990s, his team recognized that the way people treat the land on their property – specifically their landscaping, gardens, etc. – has a big impact on how much water flows into the sewer system. Traditionally, overflow strategies tend to focus on sewer pipe and tank management, which allowed engineers to manage and control where the water goes. But according to Moddemeyer, these big underground structures have a fairly linear relationship between size and cost. So a 2 million gallon tank costs almost double what 1 million gallon tank costs, he said.

Moddemeyer proposed, instead, that the city allocate funds to build a distributed, upstream strategy. He wanted to engage the public, encourage those who wanted to build rain gardens or add vegetation to their homes in Seattle’s residential and commercial areas, so there would be more surface area for rain to be used. This would make Seattle greener, make its infrastructure more sustainable and do so at a cost that would be less than putting a big tank in the ground at the end of the pipe, Moddemeyer argued.

“We wanted to think about how we can change the way landscape is managed so that rainfall stays outside and is soaked up rather than flow into the sewer system.”

There was initial resistance from the engineers, Moddemeyer said, because the plan would turn a centrally controlled system into a distributed system, in which many people would have to play a role. “Most engineers, certainly at that time, questioned how they could trust people – when a tank is there, they operate it and they’re confident in how they manage it,” Mr. Moddemeyer said.

Mr. Moddemeyer compared his plan to recycling. In Seattle, the city has decades-long contracts with companies to use their recycled materials and the city depends on individual residents to voluntarily participate. According to Mr. Moddemeyer, the city plans on roughly 20 to 40 percent of residents to recycle, so that when those percentages start drifting down towards that 20 percent, they spend more on advertising and public outreach – and this is an effective strategy.

“It’s the same with waste water,” he said. If the city estimates that 1 million gallons of rain can be stored through green practices, then the city does not have to devote as much land and capital to maintaining its combined sewer overflow system.

When the city looked at how much it cost to maintain its current setup with its underground tank, they found it was more than $10 per gallon to build additional capacity, Mr. Moddemeyer said.

This led the city to move forward with a pilot project that is now expanding to other types of buildings and locations within Seattle. Mr. Moddemeyer said other cities like Philadelphia, Chicago, New York and San Francisco are now looking at similar plans.

“The old model is, put pavement down so we don’t walk in mud. When water hits, get it out as fast as possible. The new model is to minimize the amount of pavement and then have highly absorbent soils and plants to hold that water in place. That’s why a distributed system at the top end of the combined sewer overflow system works so well.”

“Then you have this huge landscape that is working for you, rather than against you.”

A new paradigm

According to Mr. Moddemeyer, “The old paradigm is causing the climate to change, polluting water, and driving up maintenance costs [for infrastructure]. The new paradigm is about resilience and adaptability.”

Mr. Moddemeyer says that under the new paradigm sustainability projects play a more important role in traditional areas of infrastructure. He says leaders need to look at ways to use a distributed system at small scales, instead of a centralized system at big scale.

“All infrastructure systems – roads, bridges, waste water, water supply – are all built upon the weather record and are built to be reliable within a known range of the kinds of weather they’re going to get. Now climate change experts are saying, ‘you don’t know how the weather will act in the future.’ So how do you deal in the interim when you have huge uncertainty?”

“The way you deal with it,” he said, “is that you build resiliency in the system. At every scale you have little fractals of the next scale up.”