Rain Gardens: Managing Water Sustainably in the Garden and Designed Landscape

191 Pages·2007·13.56 MB·English

by  Nigel Dunnett

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stormwater water butt gully pond swale rain garden US$34.95
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planter
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Water brings our gardens and landscapes to life,
I but this once cheap and freely available
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resource is now becoming problematic with
prolonged drought at one end of the spectrum
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and catastrophic flooding at the other. This
groundbreaking book describes how to make the
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most of rainwater by capturing, channelling and
Nigel Dunnett is a senior lecturer in the Department of
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diverting it as it falls on our buildings, roads,
Landscape at the University of Sheffield, England, where
he has developed innovative research programs into permeable D paths, gardens and wider environment.
paving
naturalistic and ecologically-informed planting for
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gardens and public landscapes. He writes regularly for The ‘rain garden’ is a new and exciting concept
leading horticultural magazines and journals and lectures internal water N that combines environmental benefits with
widely throughout the UK. He lives in Sheffield. new tree swale gully green roof tank in aesthetic considerations to bring purpose and
planting greenhouse S
individuality to a garden or landscape. In this
Andy Clayden is a landscape architect, garden designer authoritative work, we see how rain gardens
and lecturer in the Department of Landscape at the follow the principles of the natural water cycle
University of Sheffield, England. He lectures in design, N
by using the landscape to slow down the rate at
i
landscape construction and design detailing. His work as g
e which water is lost to the public drainage
a designer and researcher focuses on the application of l
D system. This is achieved by employing a range of
new technologies and approaches to the creation of u
n techniques such as increasing areas of planting,
sustainable design solutions. He lives in Sheffield with n
e replacing surfaces that are traditionally ‘hard
his family. t
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landscaped’ with permeable alternatives, and
a
swale stormwater water butt gully pond swale rain garden n
Photograph of Nigel Dunnett by Jane Sebire; photograph of planter d even replacing conventional drainpipes with rain

A chains that divert rainwater from the gutter
Andy Clayden by Peter Lathey.
n
d directly into the ground.
y
Design by Dick Malt Practical and creative water management techniques C
l
a Drawing on examples from around the world,
for gardeners and landscape designers including: y
d each feature is described, explained and
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n illustrated using photographs and sketches.
Nigel Dunnett and Andy Clayden
Stormwater planters Finally, the book provides a unique directory of
plants indicating their suitability for different rain
Porous and permeable paving RAIN GARDENS
garden situations. Rain gardens are good for
Natural swimming ponds wildlife, encourage biodiversity, provide visual
and sensory pleasure and, above all, are
Rills and channels
sustainable in a changing climate.
Green roofs
ISBN-13: 978-0-88192-826-6
For details on other Timber Press books or to receive our Rainwater harvesting & storage Managing water sustainably in the
catalog, please visit our Web site, www.timberpress.com.
In the United States and Canada you may also reach us at Filter strips E
A
N garden and designed landscape
1-800-327-5680, and in the United Kingdom at
Landscape swales
[email protected] £25.00
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RAIN GARDENS
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RAIN GARDENS
Managing water sustainably in the
garden and designed landscape
Nigel Dunnett and Andy Clayden
Timber Press
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The Aztec Business Park, Copyright © 2007by Nigel Dunnett and Andy Clayden.
Bristol, UK, makes use of All rights reserved.
ponds and naturalistic Photographs by Nigel Dunnett and Andy Clayden unless
planting as part of its otherwise stated.Illustrations by Andy Clayden.
landscape. Not only does
Published in 2007by
this make for an
Timber Press,Inc.
interesting and stimulating
The Haseltine Building
work environment, but
133S.W.Second Avenue,Suite 450
swans have come in to
Portland,Oregon 97204-3527,U.S.A.
nest alongside the www.timberpress.com
office buildings. For contact information regarding editorial,marketing,sales,and
distribution in the United Kingdom,see www.timberpress.co.uk
Design by Dick Malt
Printed in China
Library of Congress Cataloging-in-Publication Data
Dunnett,Nigel.
Rain gardens :sustainable rainwater management for the
garden and designed landscape / Nigel Dunnett & Andy
Clayden.
p.cm.
Includes bibliographical references and index.
ISBN 978-0-88192-826-6
1. Landscape gardening--Water conservation.2. Water
harvesting.3. Gardens--Design.4. Plants,Ornamental--
Varieties. I.Clayden,Andy.
II.Title.
SB475.83.D86 2007
635.9'5--dc22
2006035032
A catalogue record for this book is also available from the British
Library.
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CONTENTS
Acknowledgements 6
Preface 7
Introduction 9
Section 1:Rain gardens 13
Introduction 13
Water and sustainable landscapes 14
Water in a changing climate 31
Bioretention 38
The stormwater chain 45
Section 2:The stormwater chain 51
General design principles for bioretention facilities 52
Green roofs 53
Capturing water run-off: disconnecting downpipes 76
Designing your rain garden 161
Site survey 161
Setting out a design 165
Section 3:Plant directory 169
Herbaceous plants 172
Grasses 179
Shrubs 180
Trees 182
References 183
Index 186
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ACKNOWLEDGEMENTS
The inspiration behind this book lies firmly at the feet of one man:
Tom Liptan, Stormwater Coordinator for the City of Portland,
Oregon.Tom has been a tireless advocate of the need to bring nature
and natural processes to the fore in the way that we plan for healthy
cities. His work in Portland is a testament to that dedication and
achieves environmental function and benefit in a way that is creative
and aesthetically beautiful.That is the philosophy behind this book.
We also wish to acknowledge the generosity of others in supporting
the book,in particular for donating pictures and advice.We are particu-
larlythankful to Erin Middleton for her efforts in supplying details and
pictures of the rain gardens created in Portland by Urban Water Works;
John Little, of the Grass Roof Company, London; and Vaughn
Wascovich and Vicky Ranney of Prairie Crossing for permission to use
pictures of their environmentally-sensitive residential scheme.
Finally, we wish to thank Anna Mumford, our editor at Timber
Press, for her enthusiasm and support throughout the writing of this
book,and for the friendliness of all at Timber Press.
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PREFACE
Our demand for water is growing dramatically at a time when in many
areas of the world its supply can no longer be guaranteed.Even in the
comparatively short time of writing Rain Gardensthere has been an esca-
lation in media coverage on issues relating to global warming and the
increased probability of serious summer drought.Hosepipe bans are now
common in the UK and in Londonthere is a real prospect that drinking
water will be supplied from street standpipes in exceptionally dry sum-
mers.Rain gardens represent a radical change in our thinking about how
we manage rainfall. By capturing and using rainwater we not only
significantly reduce our demand for treated water,we also have an oppor-
tunity to rethink how we design and manage public and private open
spaces in order to improve their environmental and aesthetic quality.
Rain Gardensexplores the many different ways in which rainfall can
be captured from buildings and sealed surfaces and then stored and
released within the landscape.Technical details explain how different
design elements are constructed, while case studies from the United
States and northern Europe show exactly how the concept has been
applied to a range of settings, including residential developments,
schools,public parks,city squares and private gardens.A key feature of
each of these schemes is the enhanced role of planting and planting
design. Rain gardens enable designers and those who enjoy working
with plants to argue for their enhanced role in the design of our public
and private spaces not just for their aesthetic qualities but also—and
most importantly—for their environmental and economic contribution.
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The gardens of the
Generallife, Granada, Spain,
include the classic elements
of the Paradise
Garden—water, shade, colour
and scent.
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INTRODUCTION
Without water we wouldn’t have gardens.Water was a precious resource
to the ancient cultures of the Middle East,where the concept of gardens
designed purely for pleasure first originated. The original Paradise
Gardens were stylized versions of the irrigation channels that brought
life to parched desert lands,and the biblical Garden of Eden represents
a lush green (water-fed) vision of perfection to peoples more used to
arid surroundings.We are magnetically attracted to water—throughout
history,pools,ponds,lakes,streams and fountains have been indispen-
sable ornamental elements in gardens, and more recently the presence
of water has been seen as essential to gardens that aim to attract wildlife
as well as to provide pleasure for people.We have now come full circle,
with water once again viewed as a finite and unpredictable resource,
taking centre stage in the way we plan and manage our gardens and
landscapes, not just because of its aesthetic and environmental value,
but because its presence or absence ultimately dictates what is possible.
Our view of water is changing: it is no longer in unlimited, cheap
supply,or under our control;it is instead a potentially destructive force,
and certainly one that we can no longer subjugate or take for granted.
With this new view has come a new way of working with water—a way
that is about discovering how water might behave naturally in our sur-
roundings,and working as hard as possible to allow and enable it to do
so.This way of working is an environmentally-friendly and positive
approach to tackling the seemingly increasingly frequent water-related
problems that we hear about and experience,both at home and in dis-
tant countries.
These are big issues,and it may seem strange to be discussing them
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