Bioswales – Green Infrastructure
Not able to find good soils when he came to America, Hendrikus designed his own soils. Knowing instinctively that the land itself is the basis for good water, soil interaction was the key. He designed his “EssentialSoil” custom soil blends accordingly; to act like bioswale engineered soil mixes that infiltrate, purify and, with the help of plants and soil microorganisms, remediate water.
He began designing and building what he calls “living bioswales” to handle problems of excessive stormwater caused by urbanization, poor construction practices leaving hard compact soils everywhere, and poorly designed drainage systems that were inept to handle unpredictable weather patterns. He calls them “living” not just because they contain plants, but because the entire bioswale functions within the ecosystem of the whole site. These living bioswales promote healthy fertile soils, soil microorganisms, wildlife, and a healthy sense of beauty.
In fact, Hendrikus began to design bioswales that don’t look like what most “bioswales or rain gardens” look like. His designs flow together with other elements of the garden or landscape. People are completely unaware that they are looking at an engineered drainage construction. Instead the bioswale blends in, and “lives” as the garden or land “lives”.
No Clean Soil, No Clean Water
“A rain garden”, Hendrikus will often say, “is every garden – it’s the whole garden – or it should be”. By using his EssentialSoil blends the Hendrikus group is able to turn even formal gardens or large areas of turf into sources of stormwater storage by lowering the runoff rate.
Civil engineers call these “non-point” drainage systems. It remains one of the most overlooked areas of drainage on projects that rely exclusively on catch basins and piping.
Large estates can utilize a non-point approach to drainage with bioswales and often decrease the extent of their standard drainage systems. These projects are far more “resilient” in the face of extreme weather.
A Design Imperative: Avoid Loss and Save Money
To the owners and managers of large estates, this “resiliency” will actually prevent the real loss of property, home, expensive repairs, and wildly expensive corrective construction. Bioswale construction is almost always far less expensive than the “gray” standard option. Living bioswales go further by making them beautiful and long-lived, healthy and functional, even in challenging circumstances.
A bioswale here? You’re kidding!
Many of our projects involve unique challenges. One large project was built on a very complicated “knife-shaped” ridge that extended to an ocean-facing cliff. Not only was it was built on a bird sanctuary but there was almost no room to work. Another 30-acre estate had its primary residence in harm’s way of emergency storm runoff from its agricultural fields should the drainage system became overwhelmed.
Standard drainage systems designed from “status quo” expectations are not only very costly in these circumstances; they can actually fail to protect the owner from loss of property and land.
Overall solutions in all of these cases included optimizing every part of the site in combination with an intensive living bioswale system with focused traditional “grey” stormwater piping. This involved several features that worked in synchronicity with each other to create a highly resilient site that can weather severe and unexpected storms anywhere they occur. The images here represent projects that would have incurred substantial loss if their site were not highly “resilient” to stormwater.
The key is to start with the soil and end with the entire site.
3 Benefits from using Erosion Control Soils
All of these projects used EssentialSoil Erosion Soils throughout the site. These soils accomplished 3 things simultaneously. First, they completely prevented erosion from occurring even without protection. Second, with a high infiltration rate, they provided a cushion or a buffer against high precipitation throughout the site that decreased the burden on any needed piping system. Third, the soils promoted stability on all slopes by their own intrinsic and “internal angle of friction” and by growing very deep roots quickly.
Living Bioswales: nature’s improved catch basins
Living bio-swales accomplish three things with water; they filter, absorb, and purify. Water purification takes place partially through phytoremediation, which means through plant and root growth. Absorption occurs when water slowly seeps into the ground. Filtration occurs when sediment gets trapped from plants and also settles to the bottom when the water slows down. “Grey” water systems can’t do all three things.
Living bioswales receive stormwater, they infiltrate it into the ground and purify the water through natural sediment filtration and phytoremediation. Despite their effectiveness, sometimes projects require what is known as a “forebay” or “backbay” system of bioswales to accommodate stormwater. One such project shown in the images uses one primary intense bioswale next to a road, then pipes the overflow to a secondary “backbay” or living bioswale further down the site where there was a small bit of flat land.
Together, using highly permeable soils, along with a network of living bioswales can truly make a project resilient against unpredictable stormwater events.
Stop Thinking in Compartments: The Land Doesn’t Work that Way
It’s critical, however, that managers and designers do not always think in terms of the engineered hydraulic capacity of drainage systems. This compartmentalized thinking excludes the land’s inherent potential to solve some of our worst stormwater problems.
The land itself needs to be thought of in terms of its living resiliency to accommodating stormwater. This means focusing on the entire site. It means thinking differently and thinking of the soil as part of the system and solution everywhere on-site.
Furthermore, when thinking of the land not just as a solution to a problem, but as a living potentiality for celebrating, purifying, witnessing, and conserving water over time we find interesting things happen.
We solve our problems even better.
This type of thinking requires new approaches to project insight management, It requires new thinking in our protocols and practices – and in our engineering and design. The projects represented in the images could not have been executed without living bioswales and our permeable soils.
Welcome to the Hendrikus group. We’ve been thinking like this for 30 years.
Innovation is at foot in the world of bioswales. And for good reason.
But what really is a bioswale?
It’s a type of “green infrastructure” which the U.S. Environmental Protection Agency defines as the use of natural vegetation, landscape design and engineered techniques that retain, absorb and often cleanse storm water runoff, and route excess water away from where it can do damage.
75% of the case studies show the cost of green infrastructure, such as bioswales, is the same or less than standard “gray” projects emphasizing pipe, concrete, and sometimes pumps. The benefits of green infrastructure to owners of large estates, however, take this to a whole new level; costs are no longer the central and only reason.
Besides purifying and filtering our precious water, degrading toxins in pesticides, increasing wildlife and biomass, increasing trees thereby improving microclimates, green infrastructure will help to beautify our urban and rural lands while making them more healthy to live in, on or near.
It’s no wonder that New York City is planning on installing 2000 bioswale green infrastructures. Portland has over 1300 bile swales and frequently has visitors from across the nation and from other countries observing and learning.