First, The problem
You go take a look at your storm drain system and, lo and behold, the pipes and catch basins are full of water even though it hasn't rained in a long time. The water isn't moving - there must be a major problem, right? Not necessarily. Read on.
Next, Some Background
Pipes that are always full (we engineers would call them "surcharged") do not necessarily point to a major problem - some systems were designed to do that. I have designed several storm drainage systems over the years that included pipes that would always be surcharged - I actually designed it to do that. Why? The reason is simple - there isn't enough topography on the site for the stormwater to drain away. Pipes are put in with gravity flow, but each foot the pipes drop brings them a little lower in elevation. The pipes flow to the low spot, but once there the water is significantly lower than the outflow elevation. So the system has to flood to get the water elevation high enough to actually discharge. You see this all the time in ponds and rivers. In fact, think of a dam. The water builds up behind a higher grade until it gets so high that it can actually overflow the obstruction. The same thing happens with designed storm drain systems.
Sometimes, the pond that results is a water quality or quantity pond. This is a common situation, because many projects required a pond anyway, so the water impounded by insufficient topography has another purpose - clean the stormwater before it is released. In other situations, however, the water may seemingly be just impounded, maybe in a vault, a pond, or just in the pipes. Why?
Enter the pump
When you have impounded water, it is a good time to start looking for the pump. However, even in the case of a pump, there will typically be impounded water contributing to backed-up pipes. Why? Stupid Engineers? Nope.
A correctly installed pump requires a constant supply of water behind it. You could imagine that if a pump turned on every time a little water came to it, it would turn on and off every few seconds and quickly burn out. For that reason, we back water up before a pump so that there is a decent volume there before the pump starts. The backed-up water you see may just be the water waiting for the pump to turn on.
Even when the pump does turn on, it won't pump the system dry. It can't, because it is typically that water pool that is required to remain to cool the pump motor. Pump floats (the floating mechanisms designed to turn pumps on and off) are put at elevations so that water will always remain to keep the pump cool.
So Now What?
If you see surcharged water in your storm drainage system, you may have discovered a big problem OR you may be looking at a system operating as it was designed to operate. There is no substitute for calling out a credentialed professional to take a look. Surcharged water may be a sign of a huge downstream obstruction, possibly a broken pipe, or it may just be operating perfectly.
Call out the professionals who can actually diagnose your stormwater system and help you to make sure it remains in good working condition. Click here to put in a request to have a CatchAll Environmental professional come and take a look.
Low Impact Development (LID) has been all the rage in stormwater design lately. Implementing rain gardens, pervious pavement, and bio-retention swales into site stormwater design is almost a must in many jurisdictions, at least in Washington State, the epicenter of all things stormwater. Low impact means low impact to the natural order of things, the natural drainage patterns. It means trying to mimic the drainage patterns of an undeveloped site as much as possible when designing a stormwater system to serve the developed site. How does this translate to stormwater maintenance once the site is complete?
The Old West
I like movies, and one of my favorite genres of movies is the Western. There are several Western story-lines that have been created over the years, but one of my favorites is when the new sheriff arrives on the scene. Maybe the city has been taken advantage of by the local band of thieves, the town gunslinger, or what have you. But the sheriff arrives, and all is well, or so the townsfolk think. Unbeknownst to the townsfolk, their "sheriff" is really somebody who knows nothing about how to keep the town safe from the band of marauders. Yesterday, he was the town coroner or barkeeper, today he finds himself wearing the tin star. Sooner or later, the showdown comes. It is the sheriff against the bad guys, and the townsfolk find out if the sheriff they've put their trust in has what it takes to protect them.
The Complexity of Stormwater
With a flair for the pun, I chose this topic today because I know that to those who have something to do with stormwater but who don't make their living designing it, writing about it, thinking about it everyday, the changing research, requirements, and regulations in the stormwater world must be perplexing. Its all, though, really quite simple.
Stormwater is a complex topic. Nominally, rain falls, it flows away, and its gone. That's the most simplistic way to see it and its how the world of engineering saw it for a very long time. Things have changed. Behind the simple approach is the real interest. As rain falls, it has certain effects on the natural and built environment. These effects, and the effects the natural and built environment have on the rainwater, define the areas where, in my opinion, stormwater becomes interesting. For instance, did you know that we used to model storms based on them coming and going in a general patterns depending on geography? Did you know that various organizations have 'typed' storms based on those patterns? Did you know that the pollutant load from a particular storm varies significantly depending on the time of year?
Marketing Fluff or Real Results?
Here at CatchAll Environmental, we think we have found the absolute best way to keep your stormwater costs as low as possible. We use the Catch-All® Storm Drain Maintenance Insert, inserted in your catch basins, so that keeping the storm inlets free of sediment and pollution is as inexpensive as it can be. Then, by keeping the catch basins clean, the whole downstream system, including the more expensive stormwater features, stays cleaner longer. But does the whole approach work or is it just a marketing scam?
Stormwater suffers from the “Outta sight, outta mind” issue. Once it’s gone from my view, it’s gone, right? Of course we know that is incorrect. Its disappearance from the pavement into a conveyance system is really just the start of the earthbound portion of its cyclical life. Let’s take a look at the various ways that stormwater may be headed once it leaves your site.
We have a growing problem in stormwater, and by that I mean a problem regarding things that grow. Our stormwater ponds, places where water is impounded either permanently, as in the case of a water quality pond, or temporarily, in the case of a detention pond, are a natural breeding ground for plants and trees. Those plants remove vital stormwater volume from the facility, leaving less volume for the function of the pond.
First, the Technical Speak
The Washington State Department of Ecology proposes to add a “Source Control Program for Existing Development” to the Western Washington Phase II Municipal Stormwater Permit (Permit) as soon as August of 2018. For those of you with insomnia, you can take a look at the technical document here: The Technical Document. If you'd rather just learn what this means to you, read on.
In recent conversations with various people in the stormwater world, I have been bringing up a question. The question I have been asking is, "if we were to find funding ear-marked for stormwater pollution, where and how should we apply the money?" The answer is typically something along the lines of "more technology." We live in an age where we are enamored of technology - our phone, our computers, our self-driving cars. I love it, too, but there is a problem with this answer.
Jeff McInnis is an engineer who knew there had to be a better way to help owners keep their systems in compliance.