Anyone who likes a “wee dram” of single malt will have likely heard of the role that water plays in its creation. Water is used in single malt production to germinate the barley and start the malting process. Water is used to wash the malted barley and carry the fermentable sugars as “wort” into the fermenting tuns wherein begins the mysterious journey that transforms a marginal barley beer into what the Scots call “Uisge breatha” or “The Water of Life”.
Many things influence the taste of a given single malt and one is the quality and characteristics of the water used in its production. What makes water an important part of the formula is the unique combination of chemical characteristics have been imparted to the water on its journey from cloud to still. Water may pick up mineral salts from the stream beds and aquifer it passes through. For the single malts of from Islay (pronounced eye-lah), it is often the phenols it acquires as it travels through vast hectars of deep rich peat before it makes its way into the washback.
So what has this to do with issues of water management?
Only that soil and vegetation will influence water quality. Healthy soil and plant life can be used to filter and enhance water as it makes its way through the hydrologic cycle. Water landing on roofs or pavement will pick up everything that resides on those surfaces, good or evil, and carry it along to stream, pond, lake, or ocean. Fortunately there are things we can do to improve storm or nuisance water outflow so as to provide a long-term benefit to our environment.
Bio-swales are a good place to start. Properly designed these features can provide a low cost means to temporarily impound water so that plants and beneficial soil microorganism can variously filter, absorb, or neutralize some of the more common pollutants we would otherwise flush into our dwindling water resources.
But a bio-swale is more than a planted ditch. A good bio-swale is an engineered system designed to detain or slow water flow long enough to allow plants and microbes to have their way with it. A good bio-swale is constructed with layers of different soil textures designed to promote specific actions: A surface layer of gravel or cobble slows water velocity and spreads the flow across greater surface area. A deeper layer of sandy loam allows reasonable percolation rates and good air exchange that supports a filtering network of roots and root hairs. A drainage course of sand or gravel encased sub-drainage system collects the filtrate and sends the scrubbed outflow to the storm drain and to stream, pond, or ocean beyond.
Bio-swale layout is relatively flexible and can be worked in to virtually any landscape situation. Effective use is in conjunction with roof drains, parking lots, and roadways where anything from bird droppings and industrial dust to hydrocarbons from spilled fuel and oil can taint run-off and foul streams and ponds.
Bio-swales are making their way in to more landscape designs and, along with Green roofs and Rain Gardens are providing Landscape Architects with new ways of applying old, low-tech solutions to the problems we create in our high-tech civilization.
Whether it is the right solution for your project is certainly something to think about; perhaps over a wee dram.