Opinion: Storm-Water Runoff, Why the Trickle Became a Flood

R. William Potter | March 21, 2013 | Opinion, Sandy
Ironically, the DEP's computer isn't smart enough to make the call when it comes to storm-water regulations

Ever wonder why there’s so much flooding, even after a light rain?

You can blame the runoff — or most of it — on a decision by the Department of Environmental Protection to let a computer make the call as to whether major development projects comply with key storm-water regulations.

What’s more, if the computer rules in favor of a developer, the DEP’s experts are sidelined. And the public is cut out of the review process.

That’s all of the public by the way, even downstream property owners who are on the receiving end of the runoff from “impervious surfaces,” such as asphalt parking lots.

How did this happen?

Sometime in early 2006, with no prior public notice, the DEP adopted a so-called technical manual that delivered far more than “technical advice” to project developers.

The manual is innocuously — though somewhat clumsily — titled Users Guide to Nonstructural Strategies Point System (NSPS).

Dip into the document and you’ll learn that NSPS delegates what are arguably the DEP’s most important storm-water control rules to a computer spreadsheet that’s typically filled out by a consultant hired by a developer.

If the computer says the project gets a passing score, the DEP does no more review or analysis. If the computer says the project earns an “F,” the DEP says the failing grade can’t be used in an evaluation.

In other words, failing grades don’t count.

(Full disclosure: I am the attorney for a group of homeowners and a watershed association challenging in court the DEP’s use of the NSPS.)

Looked at through the lens of another metaphor, the NSPS amounts to a Get-Out-of-Jail-Free card for developers.

But this is hardly a game, NSPS effectively negates the cornerstone storm-water rules the DEP adopted in 2004, after a long, costly public process that ended up in litigation upholding the regulations.

Importantly, these strictures make no mention of any computer-generated scorecards or rulings.

Among the regulations are nine Nonstructural Stormwater Management Strategies. The DEP deems that all nine are satisfied if the computer spits out a number assigned by the NSPS computer to a project.

These nine strategies call for preservation of “natural systems” — such as freshwater wetlands – as the primary means for stopping erosion, recharging groundwater, controlling quantity, and reducing the velocity of runoff. It also prevents “nonpoint” water pollution washed from those aforementioned impervious surfaces.

How does the computer do it? The NSPS Users Guide is ominously silent on the subject. It’s a black box justified in part because it conserves the DEP’s limited staff resources.

These nonstructural strategies compel developers to prove that they are incorporating natural features “to the maximum extent practicable” as part of each project design.

That’s a dramatic break with the past when engineered solutions prevailed, paving the way (literally) for many poorly designed developments.

No wonder the rules were quickly challenged in court by those developers who preferred the old way of storm-water control, summarized best as enclosing the runoff in piping systems.

In upholding these regulations, the court wrote as follows: “This regulatory scheme makes clear that to the ‘maximum extent practicable’ storm-water standards shall be met by incorporating nonstructural strategies into the design of any project. A permit applicant must . . . minimize land disturbance, minimize impervious surfaces, minimize use of storm-water pipes, preserve natural features, and increase natural vegetation.”

Exactly how does the NSPS computer make these judgment calls? The standards use descriptive terms that imply a fact-specific, project-by-project analysis of what’s “maximum,” what’s “minimize,” and what’s “practicable” for a site.

The rules are not numerical values or equations to be applied mechanically by a computer application. What is “maximum practicable” in one project may not be in another. What is “minimizing” land disturbance in another may be not in another. And so on.

By their very terms the nine nonstructural strategies call for skilled judgment calls after close scrutiny by DEP staff and public comment.

Now take a look at how one project got a compute-generated passing score:

Step 1: The computer asks for basic information that it uses to assign points based on which of five state planning areas” the project is located in.

Step 2: The computer tells the user to fill in the blanks on “existing or pre-developed site conditions” and then assigns more points.

In Step 3, the computer directs the developer to fill in the blanks on “proposed or postdeveloped site conditions,” and tallies up another pile of points based on inherently flexible criteria like “maximum allowable impervious coverage,” with bonus points awarded for “residential lot clustering.”

Step 4 wants “Yes” or “No” answers to a series of near-impenetrable questions such as will “proposed lawn areas be graded with lightweight equipment”; and “are any of the following storm-water management strategies met using only nonstructural strategies,” referring to groundwater recharge and the quantity and quality of storm-water runoff.

Once it has all the information, the computer comes up with “total proposed site points,” the numerator in a ratio of “proposed existing site points,” and a box captioned “required site points ratio” for a passing score.

If the ratio of proposed-to-existing site points exceeds the “required site points ratio,” the computer delivers the desired answer: “Proposed nonstructural measures are adequate.”

And there you have it. The whole process would be ludicrous if there weren’t so much at stake.

It only took two years (2004 to 2006) for the DEP to replace regulations mandating “maximum practicable” reliance on preserved woods, wetlands, vegetated swales, and like as the
primary means for preventing storm-water runoff and nonpoint pollution with a computer algorithm.

The original regulations were put in place after extended public debate and a bruising court battle. The latest rules were called into being by a process almost as mysterious (and as logical) as the black box itself.

And as the waters rise, try to take comfort in the fact that the DEP is saving taxpayers time and money.