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‘Rain Gardening’ Against Pollution Living with Our Planet Global Warming is now very much a universal concern. Although it may basically be the acting out of a natural climatic cycle that has in the past 150 years been accelerated by industrial and other forms of fall-out, it is exacerbated by human populations in order to meet their current and future needs and demands. Facile blame is constantly laid at the door of the developed world citing The Industrial Revolution, which has been defined as the application of power-driven machinery to manufacturing that began in the eighteenth century in Western Europe. Even though the western world is far from blameless, in a different manner the undeveloped areas of the world with populations spiralling out of control increasingly engender fundamental and some modern-type pollutions through sheer weight of numbers. Their progressively more rapid development generates similar needs and demands for energy and consumer products that creates waste on a vast scale. Excepting man-made pollution explosions or disasters such as Chernobyl, we also know from recorded history and must take into account that Earth itself continuously contributes occasional world-scale pollutions via natural events, for example the gigantic Volcanic eruptions of Krakatoa in 1883, which effects reverberated all around the world. And more recently, on a less significant scale, the active Soufriere Hills Volcano of the Caribbean island of Montserrat that displaced two-thirds of its population in 1995 and has erupted ever since, with a grand finale in July 2003. We have yet to learn and accept that there is nothing wrong with our God-given living planet Earth that we are so lucky to inhabit; it’s just doing its own thing. It is we who have to learn to live with it, not alter ‘it’, and adapt what we do upon it; starting with governments putting their money where their mouths are to generate new forms of suitable Energy Power, such as utilizing the Sea’s natural tidal forces surrounding our Islands to produce efficient, sustainable, new forms of clean energy power. In war and peace, in the process of providing products for use and disposal, especially by immensely dense urban populations, natural resources may be over-used or plundered and all forms of refuse and waste are created by these processes and people. There are consequently air, land and sea pollutions that unquestionably do originate from us. Post-modernist ‘progress’ has caused a lot of changes that are not for the better long-term, but instead leave us with what sometimes appears to be insurmountable challenges resulting from their consequences. However, if the progressive bright intelligences of our world alter their focus to living in harmony with our planet, instead of some wild idea that homo sapiens is some sort of supreme being that can tame it, we could at least hope to improve on the mess we are in for the future. Unfortunately, few are conscious of the planet’s own might until disaster strikes. Just as we do not completely control our lives and can only hope to manage them, because fate and chance play their part, it takes natural disasters such as the deadly Tsunami December 2004 and Northern Pakistan earthquake October 2005 to illustrate that we are not ‘in control’ of our planet either. Agriculture, Population and Protecting our Land Agriculture defines the beginning of any human civilization anywhere in the world. What has happened and is happening to agriculture in the United Kingdom is a prime example of the mistakes of ‘progress’. The English countryside was transformed between 1760 and 1830, when the open-field system of cultivation gave way to compact farms and enclosed fields, but it is again the pressure of population demands that really scuppered the superb organic natural farming method of the ‘rotation of crops’ which eventually gave way to intensified farming. At the turn of the 20th century what had been an agricultural rural population in a very short passage of time became urban. Luckily, the English retained some adherence to our agricultural history and the soil by our being not just “a nation of shopkeepers” but “a nation of gardeners”. “I leave my heart in an English Garden Safe where the elm and the oak stand by Though the years rise and roll away Still shall those watchmen stay Bold in the blue of an English sky.” Song written by Harry Parr-Davies (1914—55) From Musical - Dear Miss Phoebe (1951) Although the press of over-population now means that urban dwellings with ‘space’ for gardens are at a premium and allotments are fought for through the courts to prevent them from coming under the hammer to developers, this attachment to our Islands’ land persists. It also brings to attention the rapid rise of urbanization in the past fifty years, which in some parts of the kingdom established ‘concrete jungles’, which cannot further be allowed to spread unchecked and swallow up the countryside. It is therefore not surprising that the British love of their land is sufficient to wish to resist the march of genetically engineered plants for crops to end up in our foodstuffs and subsequently into our mouths and bodies. Even those who have never tilled the soil, wielded a spade, fork or trowel, or grown a cabbage or flower and who, through no choice of their own, trudge daily to a supermarket to buy their ‘greens’ instinctively want to protect their Land. What is worse, the very idea of ‘suicide seeds’, i.e. genetically engineered crops that produce sterile seeds or so-called ‘terminator seeds’ which end the plants’ life, goes against the grain of Nature in which all life participates in a natural endless cycle destined for renewal. This alone is a life-threatening danger to poor farmers everywhere, e.g. the poverty-stricken of the Third World would be forced to buy new seeds annually, instead of growing their own – or starve? This sterile seeds concept is a total clash with the ‘idea’ trotted out by vested interests that GM crops are being promoted to ‘feed the starving’. In fact, the best argument against GM crops, apart from the profiteering of Biotech companies, who in turn fund University research to perpetrate their will and monopolize bright brains that could be put to better use, is that they are ‘totally unnecessary’ – period! However, the march of GM is not the only difficulty that has worldwide implications. Clean water or sufficient water to meet requirements of developed and undeveloped countries alike is fast becoming a global problem. Droughts in Britain
Drought - A dried up Arm of Ardingly Reservoir by courtesy of the Sussex Ouse Conservation Society Photographer: Mark Davis – 15th November 2003 Fears generated about the effects of global warming upon the planet’s natural cycle of events or no, here in Britain if the scales are tipped too far and it interferes with the Gulf Stream Drift which keeps our islands warm, we could just as well end up with another mini or protracted Ice Age - we are on the same latitude as Moscow! Thanks to the Gulf Stream Drift, tourists love visiting Devon and Cornwall The English Riviera with its charming rustic cottages, where sub-tropical plants such as palm trees happily grow. However, our other reputation for rain used to mean that some of our tourist ratings were none too healthy; it was also well known that ‘rain stops play’ in Britain. An enthusiastic trip to our northern cities could fizzle in drizzle However, right on our door-step now there is an urgent concern, currently Britain’s water supply is threatened by ‘drought’ conditions – not just last summer, but even this winter! Britain is facing a potential water crisis, which has not occurred since the freak phenomenal summer of 1976. This is hard to believe in the South-West which has been deluged in rain this winter. Nonetheless the most densely populated area of England, the South East, including the capital London, is in one of the drier places in Europe. Put simply, London receives 24” of rain a year compared with Lisbon 28”, Rome 30” and Algiers, which is close to the Sahara receives 31” per annum.1 The problem for the capital and the South East is that 16%2 of the 60+ million accounted for British souls live in this densely populated area and take a disproportionate toll on the water supply. In the 21st century, Britain is still using a water system that was designed for about half the extant population, few of which then had indoor lavatories, let alone bathrooms with baths, showers, bidets, or kitchens with washing machines and dish-washers, nor cars to wash and gardens to hose and sprinklers. The increased population’s water-hungry paraphernalia of prosperity that is taken for granted now simply did not exist. The period from October 2004 to January 2006 was the driest in some parts of the South East since 1921. Rivers have been losing too much water, reservoirs’ water levels going down to pernicious levels. Moreover, because the 150 year old water-pipes infra-structure is so aged, damage to water-pipes is incessant. The water companies have used funds to comply with EU regulations on the water ‘clean up’ front, but not fulfilled promises of investment in sewage and repair of water pipes 3 resulting in a horrendous amount of good clean water being totally wasted and lost to domestic users. To make matters clear, this sorry state of affairs means that throughout Britain ‘lost’ water currently amounts to 30 gallons per household!4 The situation is serious; South East England has received only 25% of its normal average winter rainfall. About 3.4 million residents in the counties of Kent and Sussex are already subject to restrictions on their water use, with 2.7 million banned from using hosepipes.5 Four out of nine water companies in the South East already have some form of ‘hosepipe ban’ with restrictions on sprinklers and unattended hosepipes and others have been recommended to put a ban in place from early April at the latest!6 The reality of the crisis is literally brought home close to the English Channel where ‘Folkestone and Dover Water’, which supplies around 160,000 residents, have asked the government to allow it to install ‘compulsory’ water meters in customers’ homes.7 Lack of rainfall not only affects people and their domestic appliances, concern is growing for flora and fauna. Scientists say trees and fish could suffer in the summer because of the lack of rain to replenish water stocks.8 The situation is not yet as dire as in 1976 when millions of trees in England and Wales died in the driest sixteen month period on record. However, an expert has said that the ecology of Britain is very vulnerable to even quite a dry spell over the summer months and that the death of trees is a possibility; beech and birch being particularly susceptible. Drying water courses can have an impact on fish species such as salmon. “The small feeder streams where young fish develop may dry out, forcing the juveniles to go more quickly into the main river where they are more vulnerable to mortality.”9 Obviously, just as energy efficient homes are being better designed, water too has to be considered more stringently in future and will present many more challenges as population increase amplifies demands upon supply. Conservation of water will automatically have to extend from household domestic use to the garden. What can we do to help water conservation and to reduce pollution? Rain Gardens Capture Pollution
Rain Gardens of West Michigan Saving the Great Lakes One Rain Garden at a time Illustration by courtesy of www.raingardens.org Garden designers are about to have their ingenuity tested, fashionable ‘water features’ will have to be planned for uptake of small quantities of recyclable water flows or they may fast disappear. The garden-owning public can help by creating ‘Dry Gardens’ to accommodate water conservation. (See Herbsphere article: ‘Trees Ring the Climate Changes’ – ‘Drought Resistant Plants and Trees’ and ‘Creating a Dry Garden’.) How can we help with pollution? American research tells us that ‘Rain gardens’, (also known as Bio-retention facilities), can dramatically cut the amount of pollution in urban storm water.10 The majority of the rain that falls on our cities and suburbs lands on impervious surfaces, such as roofs and roads, where it absorbs pollutants before it drains away. The concept of rain gardens has been around in America for at least up to fifteen years, but hitherto there had not been a lot of research. Now work has been done to prove that by making a shallow depression in the earth designed to collect water, landscaped with permeable soil and hardy grasses, shrubs or trees and covered by a thin layer of mulch, can remove up to 99% of toxins.11 Mulch is important to this gardening method, the researchers discovered: “Rain garden mulch was found to be a sink for metals, nitrogen and phosphorus, but rain garden soils were a source for these pollutants.”12 In prior studies, rain gardens have been shown to provide the additional benefit of improving water quality by trapping pollutants in mulch and plantings and promoting the conversion of some compounds to less harmful forms.13 It has also been found that rain gardens significantly reduce the concentration of fertilisers, oil and particulates reaching storm drains.14 Rain gardens actually remove pollutants from the water as it percolates through the soil on its way to becoming groundwater.15 Thinking in terms of municipal or greater than domestic garden use, it has even been postulated by American research that there is the potential for engineering rain gardens to target specific pollutants.16 According to research, this form of gardening can also help reduce localized flooding by absorption of rain-water from heavy downpours, which in turn reduces the risk of drains becoming overloaded, as well as settling out sediments. The volume and velocity of runoff from heavy rain can overwhelm urban sewer systems.17 This aspect of rain gardening is important to all countries with large urban areas, for as the percentage of the world’s population living in cities continues to grow the problems of flooding and pollution are set to increase. To illustrate this, e.g. the US Environmental Protection Agency (EPA) states that more than half of the rainwater that falls on a typical city block, one with 75% or more impervious cover, will leave as run off.18 It also estimates that built-up urban areas generate nine times the amount of runoff water than woodlands of a similar size.19 Dr. Ken Potter, University of Wisconsin water resources engineering professor, is enthusiastic about the ‘groundwater recharge’ aspect of Rain gardens. Declining groundwater levels are not only important to humans, but also to aquatic life. Groundwater discharges as base-flow into streams and is “vital to their well-being”. “Rain gardens can make for better surface water quality and groundwater quality, and overall hydrological health.”20 Mr. Larry Coffman, Associate Director for the Department of Environmental Resources in Prince George’s County, Maryland, USA, who has pioneered the development of the innovative storm water management practice of Bioretention also “foresees a world in which rain gardens are popping up in tree boxes, peeking over ditches, and peering off of rooftops, not to mention blooming in yards, campuses, and parks.”21 This is not American Pie in the sky; the Anacostia Watershed Restoration Committee is considering an effort to retrofit an entire watershed in the Washington, D.C. area, no less, with rain gardens, as a way to improve water quality in the Anacostia River.22 For a step-by-step explanation and directions for how to create a ‘Rain Garden’ the website of The Rain Gardens West Michigan (http://www.raingardens.org/Index.php) is both helpful and instructive. There is also a useful list of selected suitable plants for rain gardens on website (http://www.mninter.net/~stack/rain/ ) from which to choose. The forward looking Canada Mortgage and Housing Corporation (Fig. 1) illustrate a relatively easy and attractive method of rain gardening, as well as information about its construction.
Rain Garden: Improve Storm water Management in your Yard, 2005. Source: Canada Mortgage and Housing Corporation (CMHC). All rights reserved. Reproduced with the consent of CMHC. All other uses and reproductions of this material are expressly prohibited. http://www.cmhc-schl.gc.ca/en/co/maho/la/la_005.cfm For the more scientifically minded, CMHC also illustrate natural hydrologic cycle, whereby storm water (heavy downpours) slowly infiltrates the soil and naturally filters and cleanses some pollutants, is used by plants and replenished the water table. (Fig. 2)
Fig 2. Rain Garden: Improve Storm water Management in your Yard, 2005. Source: Canada Mortgage and Housing Corporation (CMHC). All rights reserved. Reproduced with the consent of CMHC All other uses and reproductions of this material are expressly prohibited. http://www.cmhc-schl.gc.ca/en/co/maho/la/la_005.cfm This spring could possibly herald a whole new vision of how to garden to accommodate the changing climate conditions and perhaps see some of these bioretentive ideas brought into being. COMMENT: Remember when contemplating the construction of a ‘Dry Garden’ that you can use faux stones to create paths, retaining walls, patios, and many other facets of landscaping. Some faux stones are made of cement and are stained to look real, or may be home-made. In due course they will weather and be naturalized by algae or moss to look more realistic. To make a fake pond to conserve water is more of a challenge. However, if in your childhood, in a bulb bowel filled with earth, you ever used a mirror for a pond and small pebbles as the rockery surrounded by miniature plants to create a table decoration; such a design may inspire you to take that concept further. References: 1. ‘As Compulsory Water Meters arrive, we ask … If we’re such a wet country, where has all our water gone?’ by Michael Hanlon, Science Editor, Daily Mail, 3rd March 2006. 2. Ibid. 3. Ibid. 4. Ibid. 5. ‘Winter drought fears for wildlife.’ By Mark Kinver, BBC News Science and Nature reporter, 24th February 2006. Briefing by team in central London from the Centre for Ecology and Hydrology. 6. ‘Hosepipe bans call in South East.’ BBC News Online 24th February 2006. 7. ‘Winter drought fears for wildlife.’ By Mark Kinver, BBC News Science and Nature reporter, 24th February 2006. Briefing by team in central London from the Centre for Ecology and Hydrology. 8. Ibid, 9. Ibid. Quote: Dr. Mike Morecroft. 10. ‘Rain gardens ‘cut city pollution’ by Mark Kinver, BBC News Science and Nature Reporter, 27th January 2006. & original article ‘Rain gardens stem urban storm-water flows’ Environmental Science & Technology Vol. 40 iss. 4, pp. 1093-1094. 11. ‘Rain gardens ‘cut city pollution’ by Mark Kinver, BBC News Science and Nature Reporter, 27th January 2006. 12. ’Saturation to Improve Pollutant Retention in a Rain Garden.’ Michael E. Dietz and John C Clausen. Web Release date: 28th December, 2005. Nopoint Education for Municipal officials (NEMO), Uv. of Connecticut, Middlesex Cooperative Extension Office and Department of Natural Resources Management and Engineering, Uv. of Connecticut, Connecticut, USA. [Received for review 18th August, 2005. Revised manuscript received 15th November, 2005. Accepted 28th November, 2005]. Environ Sci. Technol., 40(4). 1335-1340, 2006. 10.1021/es051644f S0013-936X(05)01644-5. 13. ‘Rain gardens stem urban storm-water flows’ Environmental Science & Technology Vol. 40 iss. 4, pp. 1093-1094. http://pubs.acs.org/subscribe/journals/esthag/40/i04/html/021506news4.html 14. Storm drains or storm sewers: a large drain built to carry away excess water from a road during heavy rain. 15. ‘Rain Gardens’ by Karen Cozzetto, May 2001. http://www.consciouschoice.com/2001/cc1405/raingardens1405.html 16. From: ‘Rain gardens stem urban storm-water flows’ Environmental Science & Technology Vol. 40 iss. 4, pp. 1093-1094. Quote: Allen Davis of the University of Maryland, USA. 17. Ibid. 18. Ibid. 19. ‘Rain gardens ‘cut city pollution’ by Mark Kinver, BBC News Science and Nature Reporter, 27th January 2006. 20. ‘Rain Gardens’ by Karen Cozzetto, May 2001. 21. Ibid. 22. Ibid. |
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