Dealing with the Spectre of “Cumulative Impacts”

Walkable urban setting in Petaluma

The term “cumulative impacts” had an unfortunate effect on my formative years as a water resources engineer.  The psychological impacts were painful enough that I still twitch when I hear the phrase.  Or even when I only feel it in the air.

Earlier this week, I twitched a lot.  I feared that the cumulative impacts argument might soon be aimed at the incipient walkable urbanism of Petaluma.

I’ll start at the beginning.

I first heard the phrase “cumulative impacts” in about 1984.  I was a consultant for an electrical utility near Seattle.  They had plans for a number of small hydroelectric projects on the western slopes of the Cascades, north of Seattle.

Before anyone begins visualizing giant dams and inundated valleys, let me explain the scale.  Small hydro often means a low diversion dam, perhaps 6 feet high, a pipe bypassing a steep section of stream, and a small powerhouse at the end of the pipe where the water was returned to the stream.  A project wouldn’t be without environmental impacts because everything we do has environmental impacts.  But small hydro is often environmentally benign compared to most alternatives, especially if the fishery issues are minimal.

Although every project was unique, a typical project under consideration by the utility was an upgrade of an existing project where early 20th century settlers had placed boulders across a stream, diverted water into a carefully excavated a tunnel through a rock ridge, and constructed a powerhouse with an under-sized turbine and generator near the toe of a waterfall.

It was a great piece of history, but produced only about a fifth of the energy that it should.  The utility proposed to leave much of the history in place, while upgrading the plant to generate the inexpensive, carbon-free energy that was being lost.

The utility’s projects were well-conceived and I was proud to have a role on them.  Unfortunately, not everyone pursuing small hydroelectric potential in the region had the same sense of ethics and environmental sensitivity.

This was during years when the U.S. was highly focused on energy self-sufficiency.  Small hydro was considered an element of a self-sufficiency program, so market incentives were created to attract capital.  (Although the self-sufficiency argument was valid, the stronger argument would have been reducing the extent of climate change with carbon-free generation.  But in those years, James Hansen was still a voice in the wilderness.  We were backing the right horse for the wrong reason.  Oh well, there are worse things.)

Because of the market incentives, many private investors entered the field, filing for low-cost federal preliminary permits to give themselves time to study sites before preparing the most expensive and time-consuming license applications.

Many of sites were truly bad ideas; some were on designated wild and scenic rivers, others on creeks with strong salmon migration.  Barring a complete change in the environmental ethos, the projects were never going to proceed, but they nonetheless began showing up on lists as possible projects.

The environmental community took note, failed to understand context, and began casting about for strategies to oppose the multitude of projects.  They soon struck upon cumulative impacts.

Even better for their side, they created linguistic confusion around the term.  Only if the impacts from multiple projects are synergistic is there is an argument to study multiple projects into a single effort.   But there is little evidence that synergistic impacts occur in stream systems.  A call for a study of synergistic impacts would likely fall flat.

So the argument ended up being, after all the obfuscations were stripped away, that cumulative impact studies should be done because there might be synergistic impacts.  It wasn’t a logically consistent argument, but logical consistency often isn’t necessary for arguments to have legs.

The flawed argument was sufficiently persuasive in the court of public opinion for federal officials to begin considering rules for cumulative impact studies.  But that process was sufficiently complex, especially on the distinction between cumulative and synergistic, that the rule-making dragged on until most project proponents wandered away.

Few of the small hydro projects were ever built, even those that were well-conceived.  Even the example project I noted above remains in its previous configuration, inefficiently generating about a fifth of the energy that it might.

Instead, when new generation was required, utilities turned to gas-fired cogeneration, burning more hydrocarbons to feed the grid.  The cumulative impact argument, however logically specious, had added to the climate change momentum.  (To be clear, I’m fine with environmental permitting.  However, logically flawed environmental arguments, especially those that result in worse environmental outcomes, drive me nuts.)

About a year later, I went through a similar process in Central Oregon.  The only difference was that the instigator, rather than being a coalition of environmental groups, was a politician looking for a ladder to higher office.   Otherwise, the numbers and the results were much the same.  A great many projects were proposed, only a few were credible, and after a muddle of cumulative impact discussions, only one project was ever built, with the region instead meeting new demand with cogeneration.

That’s why the term “cumulative impacts” causes me to twitch.  And why the twitching begins as soon as someone circulates a long list of proposed projects with varying degrees of likelihood, potentially triggering public concern.

And that’s why I began to shudder when I received an 11pm email from a Petaluma Councilmember a few nights back.  In the email, she asked a number of people who knew anything about a video newly posted on the internet, describing all the land-use projects supposedly proposed for Petaluma and liberally, though inadvertently, sprinkled with mistakes.

Unfortunately, I knew the person who had created the video.  And I feared that he’d developed the idea for the video from something I’d said.  I felt like the illegitimate father of a bad idea.

Even worse, some of the initial comments on the video were similar to what I remembered from three decades before, with suggestions of a slow-down in development until the total impacts could be assessed.  To be fair to the poster, he wasn’t trying to build opposition.  His goal was more to express surprise at the economic vitality of his town.  But he inadvertently ran the risk of waking a sleeping beast.

I tried unsuccessfully to get the video taken down.  Failing that, I engaged in conversations during the week, trying to convince people that a poorly nuanced and sometimes inaccurate list wasn’t the correct basis on which to make broad land use judgments.

As in the earlier situations, there were projects for which I didn’t have any affection and wouldn’t mind if they were to die.  But once again, there were projects that were important to me, particularly the walkable urbanist projects.  Plus, I was concerned that a more poisonous environment might make progress more for future, as yet unannounced, projects.

Do I really think that a single video could slow the progress of walkable urbanism in Petaluma?  Not really.  But neither did I think that a bit of muttering in the Seattle area in 1984 would eventually grow to unwind a number of well-founded hydroelectric projects that could have slowed, at least a little bit, the progress of climate change.  So I choose to be cautious.

As I write this, I note that I’m coming close to a favorite subject of mine, the interface between public opinion and technical knowledge.  Land use is only one of many areas for which this is of crucial importance.  Indeed, managing that interface may be the biggest challenge in a democracy.  But I’ve already taken enough of your attention for one day.  I’ll write about the interface in my next post, bringing this subject to a close.  At least, I hope it stays closed.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)