The flooding in Millvale, Etna, Turtle Creek, Wilkins, Plum, Murrysville, Export, and North Huntingdon on August 9, 2007 is a sad reminder that something is wrong in this region, that something as natural as rainwater has become a curse. Talk to people in those towns and many others around Allegheny County and you’ll hear comments like these. “I’ve lived here 70 years, and we were never flooded this often.” “Every time it rains, we get water in the basement, and not just in hard rains.” “We have water coming over the lawn, and running past the house.” “We’re paying taxes on property we don’t own anymore. The stream is washing away our lot.”
When water is filling basements, coming through front doors, and running a few feet deep to engulf cars in the street, who can think of anything but curing the problem? Curing it, that is, once people have recovered from their ruined furnaces, washers, driers, water heaters, furniture, cars, and bank accounts.
The thing is, what we’re seeing is not occasional flooding caused by very heavy rainfall. It is the sign of a chronic breakdown in water flow patterns. We’re faced with two problems and, of all things, an opportunity--the river contamination problem, the flooding problem, and the stream recharge opportunity. They’re linked at their source.
- This region has a severe problem with failing sanitary sewer systems polluting our rivers with sanitary wastewater. High volumes of rainwater overwhelm sewage treatment facilities and overflow sewage conveyances, putting untreated sewage into our streams and rivers after nearly every storm. So? Well, aside from the fact the EPA is breathing down our municipal necks over river pollution, it means that on those gorgeous, blue-sky, low-humidity days the day after a rainstorm, we can’t go in the water. Not if we’re smart. Get this. Each year, for half the days in our region’s water recreation season from May to September our rivers are under a health advisory. That means that you shouldn’t go in the water, be near the water, or get much water on you unless you want to get sick from the fecal coliform that is in the rivers. We know that this is a multi-billion dollar problem that will take a decade of massive inter-municipal cooperation to repair. But it has to do with water flow—and infiltration.
- So does flooding. Floodwater starts upstream, of course. Streams have stream sheds, the lay of the land that determines how rainfall finds its way to a particular stream. That’s how streams came about a long time ago, by rainwater cutting their channels. The question is how and why this natural phenomenon has become a problem. There are two causes, but we tend to recognize only the first, which is when precipitation fills the stream channel beyond its normal banks and water flows into what is, or was nature’s management scheme for this situation—the flood plain. The problem here is not with the water, but with us. Humans have a habit of settling in flood plains for a lot of seemingly good reasons like flatness, transportation, and convenience, but when we do, we set ourselves up for normally recurring damage. Think not only Hurricane Ivan here, but New Orleans 2005, and even downtown Pittsburgh. Expensive patterns.
The other cause of too much water in a streambed and flood plain downstream doesn’t have to do with high rainfall. It has to do with reduced or degraded land upstream. This is the problem our region has not come to terms with. Nature’s heavy rain management system is infiltration and related recharge of groundwater. In undisturbed natural settings, more precipitation soaks into the soil and subsoil and relatively less runs off to accumulate dangerously somewhere downstream. For infiltration, forests are better than fields, fields are better than lawns, and lawns are better—a bit better—than paved and built surfaces. In a forest, leaves, branches, bushes, and ground cover slow the fall, buffer the ground, and allow water to soak in. The obvious opposite effect is caused by roads, streets, parking lots, and roofs. When water flows downhill, by way of surface runoff or storm sewers, it invariably concentrates, and when it concentrates it causes the problems that Millvale, Etna, Carnegie, and Turtle Creek are getting altogether too familiar with.
- So, where should the water go? Into the ground, where it becomes a resource, not a curse. When rain (and snow melt) infiltrate into the ground, they recharge groundwater, and groundwater recharges streams. Adequately recharged streams flow all year, higher in wet seasons, lower in dry seasons, but all year, supporting fish and other wildlife in the process. Streams deprived of natural recharge disappear or shrink to a trickle in the dry season, and aquatic life goes with them.
Here’s where the opportunity comes in. Land development and stormwater management practices that allow infiltration to take place make available the water that feeds streams—the streams that are a real economic and quality-of-life asset to our region. Communities like Murrysville are seriously considering ensuring that Haymaker Run (a high quality cold water fishery) can support trout year-round. Not stocked trout, but naturally reproducing resident trout! That stream makes Murrysville a more appealing place to live, with higher property values, but it can’t happen unless Haymaker Run has an adequate base flow all year. Imagine. And imagine, even further, something similar in Pine Creek and Chartiers Creek and Girty’s Run and Turtle Creek.
Okay, okay. When we see pictures of Millvale or Export last week or Millvale, Etna, and Carnegie three years ago, it’s pretty hard to give much time to the idea that our streams could be looked at with pleasure rather than dread. First of all, we need to protect lives and homes in these places. The Corps of Engineers among others has to make the infrastructure changes to do that. And probably in certain locations the smartest thing is that residents and businesses move out of the most risky spots in flood plains in order not to suffer the same sort of damage time and time again. But notice, this is still reacting, not planning and solving.
For the long-term, correcting and responding at “the end of the pipe” and after the fact is no answer, or maybe just the most expensive answer of all. If we focus on channeling flood water to prevent damage, we are starting at the wrong end of equation, where our only option is to repair. We need to prevent. And with water, this means looking upstream, to where the water originates and either stays—naturally—for a while, or concentrates and comes roaring down streambeds and valleys and streets to damage property and ruin lives. Let’s face it, all along we’ve thought of stormwater as a waste to be gotten rid of, as fast as possible. If that is our outlook, then concrete channels fit the bill—concrete channels that move high volumes of water out of our area downstream as fast as possible. Downstream, to become someone else’s problem.
What are we going to do about this? For one thing, at the root, the loop has to be closed between the benefits and costs of business as usual. As things stand now, those who benefit from development that causes stormwater problems don’t face the indirect downstream costs of their action, those who suffer damage from stormwater don’t share in the benefits or receive restitution from those who do. Downstream municipalities can and do sue upstream municipalities, but that route is tough and slow. Let’s be clear, upstream municipalities are not necessarily precisely at fault; it’s just that they’re the legally responsible entity. And anyway, litigation is still a reactive and after the fact approach. Wrong end of the design and legal pipes.
What gets us to the right end of the pipe, the best place to intervene in this broken system? Best management practices, or BMPs for short. BMPs can focus on design, engineering, construction, regulations, and legal questions. They are the right way to do things, and are usually the cheapest in the long run. (Remember that the cost accounting here has to include post-flood restoration and compensation and the cost of infrastructure repair and construction. Do developers want to foot those costs?) BMPs can be requirements. They can also be the default mode of doing something. How do we implement them?
- Municipalities have to adopt and enforce effective codes and ordinances that require innovative BMPs for development and redevelopment of land.
- The General Assembly has to pass new legislation that will allow municipalities to put some teeth into zoning and planning ordinances.
- Developers and builders have to get smart and integrate innovative stormwater BMPs into their development plans.
- Municipal planning commissions and zoning boards, as well as the engineers and solicitors they rely on for technical guidance are going to have to become versed in innovative stormwater BMPs.
- Municipalities have to work together across jurisdictional boundaries to solve stormwater problems the only place where they can be solved, upstream at their sources, starting with the recognition that upstream actions with downstream consequences are an upstream responsibility.
- Municipalities might have to form public authorities with the single charge of investing in and managing stormwater management the same way that specialized municipal authorities manage water supply and wastewater treatment.
To make a long story short, our focus has to be on assets, not liabilities, or we’ll never hit the target.
Center for Environmental Research and Education
Duquesne University
kabala@duq.ed
