WWaatteerr ffoorr oouurr iissllaanndd ccoommmmuunniittyy

MountMount Gardner Tunstall Gardner (727 metres) Bay

Josephine Lake

Grafton Lake Honeymoon Killarney Lake Lake

Seymour Bay Eagle Cliff Snug reservoir Cove

Aerial map image of Bowen Island, viewed looking to southwest, created by draping a mosaic of aerial photographs over a digital elevation model. Image created by Ryan Grant.

Geological Survey of Canada Miscellaneous Report 88, 2005

By: Bob Turner, Richard Franklin, Murray Journeay, David Hocking, Anne Franc de Ferriere, Andre Chollat, Julian Dunster, Alan Whitehead, and D. G. Blair-Whitehead.

Advisory Committee: Stacey Beamer, D. G. Blair-Whitehead, Ross Carter, Andre Chollat, Julian Dunster, Anne Franc de Ferriere, Bill Hamilton, Ian Henley, Dave Hocking, Will Husby, Murray Journeay, Denison Mears, John Reid, Mallory Smith, Ian Thomson, Bob Turner, Dick Underhill, Alan Whitehead, Dave Wrinch, Dave Yeager.

Natural Resources Ressources naturelles Canada Canada BOWEN ISLAND

c Her Majesty the Queen in Right of Canada 2005 Hi, I'm Raindrop. Come with me and explore the story of water on Bowen Island. BOWEN ISLAND

We are a small island surrounded by salty ocean water, and so there are limits to our freshwater supply. Yet all life - people, other animals and plants - rely utterly on a continued supply. So we need to answer important questions: Do we have enough water? Are we using it wisely? Are we protecting our drinking water

supplies? Are we leaving Bowen enough for nature? Island

Vancouver

Pacific Victoria Ocean MountMount Gardner Tunstall Gardner (727 metres) Bay

Seattle

Josephine Lake

Grafton Lake Honeymoon Killarney Lake Lake

Seymour Bay Eagle Cliff Snug reservoir Cove

1 Watershed c by Pauline Le Bel 2002

Water Restless Water shed singing the shore pebbles since the beginning; dancing the moon silver beads of life how we long to contain you. falling from the sky. In our carelessness we alter your flow Living water we squander shed we poison for the love of your gift. greening things. Living Water Clutching our hands cleansing we watch you slip away nourishing drop by drop. healing. We forget to bow our heads.

Sacred Water Mother of all life forms when will we gaze upon yet formless the still mirror of your face yielding and remember to serpentine river bed; our watery beginnings blessing fingers the amniotic cradle dipped in still ponds; of our Mothers? accepting the scoop When will we feel of a child’s rubber pail. the oceans flowing through our veins, taste our salty tears? Powerful Water When will every water-loving changing everything cell in our body in your path cry out: wearing smooth what we do to you the hardest stone we do to ourselves? in your urgency to return to the sea Oh, Troubled Water in this neverending prayer one shining morning of renewal. we will gather we will stand Island Waters ready and willing precious to protect you vulnerable to honour you. children of the salty womb we call you Grafton Honeymoon Josephine home of the red swimmer.

2 Water in our lives: how we use it

drinking and cooking 4% Water - essential to life laundry garden and dishes watering Imagine life without water. Impossible! 16% People, animals, plants - we all need Where does all that 20% water to survive. water go?

We flush a third of the bathing and water we use down the cleaning toilet. In the summer, 28% watering our gardens can cause household use to jump 30%. toilet flushing 32% r e n r u T

. B

Hidden water use

Water is used to produce the food we eat and the products we use. ? For example, leaking manufacturing a toilet car uses hundreds of thousands of ? litres of water. leaks dripping tap

water supply leaks to septic field

3 Necessity - the mother of conservation. By international standards, 600 Canadians waste a lot of water. ) s

e Cheap and seemingly unlimited r t i l includes school supplies discourage conservation. (

500 How we

n and commercial use But water districts on Bowen that o

s suffer summer water shortages have r measure e

p become very efficient water users.

r 400

e up! How did they do it? p

e s

u 300

r e t a w

y 200 l i a d Bowen IIslland e

g 100 a 2001 r e v A 0 r l f r y y y e t a A n e a f e v c K c e i a a a i d S e y l t u r U a t a d n r n C a B B B o U l c s n e a s e w l n e i a r I e e n D w F K l a e v a C g u V S l s w o a a r nt o C nl E B e o u t i B a g T e r e R G Raindrop says: Use water wisely.

User pay!

Summer water use in Eagle Cliff dropped 70% when household meters were installed. When we have to pay for what we use, we tend to use less. Meters also identify leaks in the pipe system.

reservoir many full service Crisis! built houses built summer '95 600 water My! How our reservoir runs dry twice metres water use installed in all has changed. homes

400 more 4 3 67 8

P ROG RAM MES gardens

well serves leaks Average daily some cottages detected water use ts Bluff Creek en per person id increased "water war" increased es (litres) r conservation appliances d 200 first n u permanent ro outhouses r- residents ea y g n si ea cr Eagle Cliff water in 60 from creek Water Use first summer cottages only ? cottages 40

1920 1930 1940 1950 1960 1970 1980 1990 2000 Eagle Cliff water use through the years

4 Where does our water come from?

The Myth of Mainland Water Supply North Shore Mountains

Sunshine Bowen Island Coast

g

r o u n d w a te r

gro flow undwater flow

My water comes from Mt. Baker!

Though some islanders guess that their springs or wells flow from Mt. Baker or the North Shore, there is no scientific evidence for such claims. All indications point to island rainfall as the source of Bowen's fresh water supply.

Bowen Island

wat er ta ble Howe Sound zone of fresh ground water

fractured rock salty ground water

Island groundwater systems

Ocean islands such as Bowen Island are surrounded by salt water. This is also true underground. A limited zone of fresh groundwater underlies the island. This freshwater zone is fed by rainfall to the island, and is surrounded by salty groundwater that underlies the ocean.

5 Raindrop says:

All our water comes from rain that falls on the island.

It all falls from the sky

Rainfall feeds Bowen's entire fresh water supply. Moisture from the Pacific is blown evaporation eastwards and falls as rain. Rainwater flows storms into streams to be carried quickly to the sea (perhaps with a pause in wetlands or Pacific Ocean lakes) or sinks into the ground to join Vancouver the slow moving groundwater system. Island Shallow groundwater returns to the surface as springs, adding flow to streams. The island's fresh Strait of groundwater is entirely Georgia surrounded by salty s m groundwater that a Bowen Island e underlies the str seafloor. s t r evapo- s e stream a m transpiration lake s

s fresh p r i groundwaterr n Howe g Howe s system s Sound g Sound in r p s

salty groundwater

? Mystery stream supply

Some streams on Bowen flow year round, even through the summer dry season. When it hasn't rained for weeks, where can the water be coming from?

6 Water shortages? But this is a rainforest!

Are more droughts coming ?

Scientists predict that in the future southwestern British Columbia will receive more winter rainfall, The problem: but longer and hotter summer dry seasons. How our summer dry season will this effect the supply of water on Bowen Island? er How can we have water d m e shortages when we get so much m m u a rain?. Because so much of our s n 300 k d 1.5 to 1.8 metres of annual a e rainfall comes during the winter p and runs quickly to the sea. The summer 300 land can't store enough of our 200 dry winter rains, so water shortages season occur during the summer dry 200 100 season. Hood Po Av int erage Weathe m r onthly Station rainfall 10 (1992 (mi 0 -1998) llimeters) Jan. F eb. Ma r. Apr. May Ju Cow n. Jul. an Point Aug. S Weat ep. Oc her Stati t. Nov. (199 on Dec. 2-1998)

to atmosphere rain and snow on evaporation island to atmosphere

reservoir wetlands Howe surface evapotranspiration Sound storage by island vegetation deep surface infiltration water garden withdrawal watering

ocean outfall disposal wells Doing the math: septic not much storage field disposal underground Most rainwater returns to the storage in deep groundwater atmosphere through plants and system evaporation. Much of the rest is carried quickly to the sea by streams. Some stream water is stored for days Limited re-supply! to months in wetlands, ponds, lakes, and reservoirs. A small amount infiltrates the ground, Based on research in the San evades capture by plant roots, and can be stored Juan Islands, it is estimated that for months to centuries in the slow-moving only a small percent of our groundwater system. annual rainfall, likely less than 15 cm of rainwater, becomes part of deep groundwater storage.

7 B o B

0 Number of Bowen w Dif a T B Bowen Island y e u l B u n n households supplied A e sources on a 2 4 6 8 s w y t 0 0 0 0 ferent water a

a l 0 0 0 0 0 m l t B. Turner k e i l r o m a d d w l w s i c u e t r a e r p i e g t l e t a l r n e e

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l t r a e I u v t s h o n e i i l r s t p l r i y s c t s a r r

W e i W e v o o J n n a a o u c u t a m a s e L e G d e r a r t L t c r p k a c a

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p u e s u d r y t r n g i i s o v t

t n a w e water Island. Sowecontrolthefutureofour almost allofitcomesfromBowen away and manufacturedgoodscomefromfar Think aboutit.Mostofthefood,energy

t m a e e r l e l a W . Onlyourwaterishomegrown, , it'sforustodecide! H a S o t o w e u e r n p , d d

r w r t i i v asthma andglobalwarming. pollution, causingproblemslike trucking watergeneratesair creates wastecontainers,and disadvantages: It'sexpensive,it convenient, thereare popular Bottled waterhasbecomevery l e h l a e l l t d e

e t

h l o e c B

. Whileitseemssafeand f a o o l R R

r t future. Itisforustodecide. have stewardshipoverits is alocalresource,we local resource.Becauseit It trulyisourmostvaluable comes fromBowenIsland. But almostallofourwater use comefromfaraway manufactured goodswe food, energy Think aboutit.Mostofthe r a a e t a a e i i l s s n n i e k k s g the localresource d d s d s r o r n : : o o

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i - h o , c D e ater , and o n o r m e

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, k r r o

n w m o a w ? t e r . Watersheds everywhere!

All the land area that drains into a stream system is called a watershed. Most areas of Bowen Island drain into some stream stream, so it is likely that you watershed live in a watershed. A water boundary supply watershed is the part of a watershed upstream of a water supply water supply intake. Many parts surface watershed of Bowen Island are water runoff supply watershed areas. Do dam and you live in one? reservoir

Howe Sound

Mt. Gardner Grafton Lake Water Supply Watershed stream flow Grafton Lake

water Living in intake distribution our water dam to Cove Bay supply to Cates water system watersheds Hill

Queen Artisan Community Vancouver protects Charlotte Square School water quality in its Heights watersheds by restricting Millers access. Things are different Landing on Bowen. Some water supply Deep Bay watersheds lie within forested Snug Crown Lands and are relatively Cove pristine. But others, such as the Grafton Lake water supply, include Scarborough residential and commercial areas, roads and livestock. All of these uses represent potential sources of contamination. Should we be concerned?

9 The clean water factory: forests, streams and wetlands

Hi-tech forests? How they work for us.

Our forests, streams, lakes, and wetlands provide an amazing service to us, clean water! They have evolved over millions of years of “research and development”. Forests act as a giant filter. Rain infiltrates the porous organic soils and percolates slowly to streams where it is gradually released as clear water. As a result, forest streams commonly run clear even during storms. y b s u H

. W

rainfall The modified landscape:

rainfall a damaged green The natural forest: infrastructure a healthy green infrastructure

storm-surge infiltration runoff

moderated runoff ru no ff shallow groundwater ocean

ocean

Forests most Rapid runoff slowly rainfall from bare plant becomes transpiration release surface land causes rainfall to runoff erosion and streams, floods. organic limiting soil flooded moderate floods. stream flow erosion during b are storm min mineral mineral era water sinks l so soil into forest floor flow to soil il streams as shallow erosion ground water

Forests: Most rainfall Cleared Land: Most rainfall becomes shallow groundwater becomes surface runoff

Stream “tornadoes”

In contrast to forests, rain does not easily infiltrate bare mineral soils exposed in disturbed areas. Instead, rainwater flows on the surface, eroding and carrying away fine sediment. During storms, streams flood quickly with muddy waters, eroding banks and filling channels with sediment. Such floods are like a tornado, wreaking havoc to stream life.

10 Skunk cabbage, a wetland indicator plant.

Raindrop says:

By protecting our land we protect our water. r e t s n u D

. J r e n r

u Grafton Lake hosts extensive and important wetlands T

. B

How wetlands work contaminants and sediment dissipates is filtered provides stream critical wildlife energy habitat

cleaner water outflow

groundwater flow

bacteria breakdown contaminants slow release saturated peat of stored water stream stores water

Wetlands: nature's sponge and filter

Wetlands swamps, marshes, bogs, and fens provide many services. They filter stream waters, store water, and offer critical habitat for many plants and animals. Wetlands fill with water during rains and slowly release water through droughts. Before we understood their critical role, we used to ditch and drain wetlands to create lawns, pastures, or farms.

11 What's the problem? poorly constructed dry road crosses "minor stream dry stream bed"

Muddy water from small tributary enters Bowen stream.

low summer flow

Every stream counts. Even small dry ones.

Water enters streams through many small tributary channels. During winter rains, water flows in these channels. However, this surface flow usually disappears

during the summer dry season. r e n Some might view these seasonal r u T

.

channels as unimportant and not B worthy of protection. After all, they only flow part of the year. However, any channel, muddy road regardless how small, can deliver damaging silt to the stream ditch water system during winter storms. flows into Therefore, even small seasonal stream streams need protection.

siltation high damage winter flow Oh Oh! road ditch channels muddy water into stream

12 Winter high flow

well stream

water table water-filled gravel soil

Summer low flow

well dry soil stream bed

water table water-filled insects and gravel small fish

Underground streams? Every stream has one.

Every stream flowing over a bed of gravel has an underground stream. This underground water fills the gravels and flows slowly downstream under the stream bed. During the summer dry season, the water level can drop below the stream bed, creating the appearance that the stream has completely dried up. But water may still be flowing in the gravels. Anyone who draws water from a shallow well beside a stream knows this can be true- a well continues to produce water after the stream goes dry. This hidden underground river r e This stream looks dry, but water n

r provides refuge for insects and even small fish u

T still flows within the gravels.

. through the dry periods. So a stream can still be B flowing even though it looks completely dry.

13 Roads under construction, and newly cleared lands are major sources of turbidity on Bowen Island. A little mud never hurt anyone - or did it?

Muddy water or turbidity is a major water contaminant on Bowen Island. Turbidity plays havoc with water treatment systems, reducing the ability of chlorine to disinfect. Muddy water also degrades stream gravels. The spaces in clean gravels are home to all kinds of life fish eggs, insects, and even small fish. Silt clogs these pores, reducing life in the stream. r e n r u T

. B

Are ditches a part of stream systems? You bet!

Construction of ditches have added many miles to our stream system. Many small streams drain into ditches, and most ditches drain back into streams. So whatever goes into ditches, ends up in our streams!

Ditch runoff during winter r e n

r storm u T

. B

14 shade cools stream water

walking trails wildlife corridor wildlife habitat water filtration water erosion filtration control groundwater recharge riparian zone forested corridor

Forested corridors: vital to stream health Shoreline wetland, Maintaining forest corridors along our streams is essential to stream Josephine Lake health. Forests filter water, and provide shade to cool waters during summer heat, logs that create pools and riffles, and wildlife travel corridors and habitat. They also provide walking trails for us!

k oo Br Bowen

Road Adams

Crown land B

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Josephine u T

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a a protected land B o o

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o J Bowen

Crown land Road 1999 Adams Investing in Greenways: Crown B land

o

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our recent progress S e

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e B t

Bowen's green infrastructure is in good r o

o wetlands condition. We invest in it by protecting it as k Josephine

d parkland. Over the last several years, d Lake

a a

o o

Bowen Island Municipality has negotiated R R R oa d l

a green infrastructure protection with l a e

n S landowners seeking to develop their lands. i h

wetlands p A network of greenways has protected e s

o streams, wetlands, and lakes in the J Josephine Lake area. 2005 Crown land

15 Water stored underground:

shallow dug well beside stream vital and vulnerable shallow drilled wells (licenced surface dug well water intake) in rock

drilled well in soil

watertable s r d e f e i t till (hardpan)

u high yield stream a q d

i gravel aquifer l a

o t s n n e o m c i high yield sand and n d high-yield u e gravel aquifer

s fractured

r rock e n r

d aquifer u e T . r low-yield k B u c t fractured o c r a

r Aquifers yield water via wells rock f aquifer

Tapping into water stored underground Water stored underground in cracks and pores Any body of rock or sediment that yields useful amounts of water is an aquifer. Bowen Island has two types of aquifer: fractured rock, and sand and gravel layers. The amount of water stored in fractured rock is typically limited, and these aquifers can run low during the summer drought. Sand and gravel can store more water and these aquifers are less likely to dry up in the summer. Shallow dug wells can dry up as the water table falls during the summer.

So what is groundwater?

Rainwater percolates into the earth. Soil and rock are like a giant sponge, full of holes, typically tiny pores and r e

n cracks just millimetres in size. Below the water table, r u T

these holes are full of water. This is groundwater. . B Groundwater slowly travels through connected pores and cracks just centimetres to infiltration plant intake meters per year. of soil water

infiltration unsaturated sand and zone gravel water table aquifer silty layer

sand and groundwater zone Water stored gravel aquifer

underground in fractured cracks and pores rock aquifer

16 Mt. Groundwater flows from upland recharge Gardner areas to valley discharge areas infiltration le tab er at w recharge area Josephine Tunstall Lake Bay

runoff spring w o recharge l f

area r e t di a sch w ar spring d ge n Cowans are discharge u a o Point area gr discharge spring area Terminal Creek fresh ground water salty ground water Ensuring our aquifers replenish

Most recharging of aquifers occurs in forested uplands and valley slopes. But land clearing, road building and ditching reduce water infiltration by creating impermeable surfaces and diverting water into ditches and streams. Infiltration ponds along ditches can increase the return of water into the groundwater system. r e n r u

T Mt. Gardner from Grafton Lake

. B Underground lakes and rivers? Mountains as water towers Not on Bowen. Large underground streams and lakes only occur in limestone cave systems. Limestone is unique as it Mount Gardner and our other forested mountains play a vital role in dissolves in water, allowing caves to form. water capture, storage, and delivery on Bowen Island. As mountains Bowen's granitic and volcanic rocks do not they force moist air masses to rise, causing additional rainfall on the dissolve in water and so lack cave systems. island. Small depressions on their forested slopes allow infiltration of rainwater, recharging the groundwater system. Because of their tremendous bulk, our mountains have a huge capacity to store groundwater. They act as giant "water towers" for the island. Groundwater moves slowly downward from these "water towers" under the pull of gravity. Some of it feeds springs that flow into streams along lower slopes and valley. Other groundwater flows directly into valley aquifers and lakes."

17 Protecting the balance

Groundwater storage is like a bank account. The balance falls when withdrawals exceed deposits. Nature makes deposits through rainfall, and withdrawals through leakage of groundwater to streams and the ocean. Our wells represent further withdrawals. If total withdrawals exceed deposits, we deplete our groundwater storage. Do we know if we are draining our account? Be a good Raindrop neighbour. says: Turn off your hose.

fall/winter recharge long term depletion w at summer er ta dry season height bl e g le of in b s ta water ri r w fa e a lli table t te ng a r t w ab le

January June January June January year year

Water table ups and downs through the seasons

The amount of water stored underground changes through the seasons. As winter and spring rains infiltrate the ground, stored groundwater increases and the water table rises. When the rains stop, the water table falls as groundwater leaks into streams and the ocean. Well pumping also removes water and lowers the water table. Excessive pumping of groundwater can result in long term depletion of groundwater storage.

Excessive pumping can reduce flow in streams

a) okay Oops! I dried up the stream

Groundwater springs feed streams year round. They are the only source of stream water during the dry season. A pumped well draws down the nearby water table. Excessive pumping for an extended period of time can water stream lower the water table over a broad area. This can divert table groundwater from streams and even cause streams to dry up. Nothing damages a stream like taking away its water!

b) overpumping

Are we depleting our groundwater? well To determine whether we are overpumping goes dry stream our island aquifers, we need a series of goes groundwater observation wells on Bowen. dry These are unused wells where water table levels can be regularly checked to determine wate rtable long-term trends. Some groundwater monitoring has started on Bowen but more drawdown of watertable observation wells are needed.

18 salt-contaminated well Howe Sound

drawdown

watertable before boundary after pumping pumping sandstone

watertable salty after groundwater pumping fresh groundwater boundary before mudstone salt water pumping intrusion

Coastal invasion: Salt water intrusion

Salt water intrusion occurs when the boundary between salty groundwater below the ocean and fresh groundwater below the land shifts landward, resulting in coastal water wells becoming salty. This boundary is dynamic and held in position by the pressure of higher elevation fresh groundwater pushing seaward. Excessive pumping of wells on land can reduce this seaward pressure, allowing the salty groundwater to advance landward. Saltwater intrusion is an issue on several Gulf Islands, particularly on relatively flat or narrow peninsulas. Saltwater intrusion is less likely to occur on Bowen Island because our higher rainfall and mountainous island create a stronger seaward pressure within our fresh groundwater system. arsenic contaminated wells "Natural groundwater contamination: arsenic water table Arsenic occurs naturally as Howe minerals in the rock of Bowen Sound soil Island, as it does elsewhere. The distribution of arsenic minerals is highly variable. Where it is abundant, it contaminates nearby groundwater. Drinking water saline fractured with elevated levels of groundwater arsenic rich rock arsenic is a health hazard. minerals Many wells on Bowen Island r contain some arsenic; a few arsenic ate ndw wells exceed allowable contaminated rou g flow arsenic levels and are not groundwaters permitted as a source of potable water. high concentration of moderate concentration of arsenic in groundwater arsenic in groundwater

19 s p i o l l i

l c h

Reducing risks:protectingwaterquality t o e a n a n " t t k a s c i n

o l i w e n g e i l a m i

t f b W population. W extensive forestlands,ourcleanwater factory f infrastructure isvital.Indevelopedareas, we needtocommit“best practices”to n minimize theriskofcontamination. h l e a u " e areasmallislandwithgrowing n

c e s t t n e e t p r . Protectingthisgreen i t a i clean waterfactory c Protecting our e areblessedwith s e s t t i l l t i s n

f e g e d

n p i c m o e l n u c e s t d o r m n

e t s v t r b a a

e a e t D p r e n e r d

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- Killarney Lakevalleyfrom Rivendell

p r c s o o p n i t l l t s e a i c n e t d i m n

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s l f a r i a t t r l r n t e t e u e e d s c r r r e e t

e s r d v u d o p i p r l y Reducing risks: protecting water quality

Doing it wrong - degrading our water

pesticide and herbicide muddy storm runoff water supply spraying from land clearing reservoir uncovered manure pile and road building

animals in stream

failing septic field effluent heating leachate from rises to surface oil tank treated lumber leaks fuel spills

So what's the problem?

We can learn from past mistakes. Turbidity is a problem for many water systems - its source is r

e road construction, land clearing, and poor n r u T

storm water management. Failed septic . B systems and poor livestock practices can lead to bacterial contamination. Leaks from buried fuel tanks, fuel spills, and illegal burn piles have locally contaminated groundwater. We should also be concerned about risks from herbicides and pesticides.

21 Your septic field: a friend that needs maintenance

Septic fields are safe, economical, low maintenance facilities for sewage disposal on Bowen. But they do need an annual check. Waste water flows into a tank where solids are trapped and bacteria break down When things wastes. Liquids flow into the drain field and percolate go wrong. into the soil. Soil bacteria purify the effluent, producing clean water that becomes groundwater. septic Septic fields fail tank when drain fields il so clog and septic drain field effluent rises to the surface and flows overland, gravel groundwater contaminating flow wells and streams. Wells downhill from a failing septic field are only protected if they are capped Do you know soil b Raindrop acteri and grouted properly. where your brea a asks: wat kdow Otherwise, septic effluent can asks: septic field is? er tab e n le ffluent enter a well from the surface.

clean en efflu ters ent groun s dwat ystem er Contaminated water supply: Effluent from failed septic field enters unsealed well

Safe water supply: septic effluent uncapped rises to surface well sealed A sealed well uphill sew er effluent well cap from septic field high clogged drain no grout water field seal grout septic table seal field contamination of water supply w absorption ater table purification ground water flow

ground water well cap flow Is your well water Safe water supply: pipe protected? A sealed well a safe to house distance from septic field casing Trouble occurs when cement contaminated surface seal septic sealed water leaks down into field > 30 m well cap static water wells. To prevent this, drawdown level properly sealed wells absorption grout have grout injected w ater table purification seal le ab between the well casing rt te a (steel pipe in the upper w well) and the well wall, and a cap is placed on ground water standing the top of the casing. flow water However, many wells in well are not properly sealed. Is yours? pump

22 Healthy forests provide the best water supply protection r e n r u T

. B

The Cove Bay water supply intake is in Grafton Lake r e n r u T

. B Source water protection is cost effective

Many jurisdictions in North America have decided that source water protection is the most cost effective way to protect their water supply. On Bowen Island we need to protect lands within our water supply watersheds. Our forested mountains and

uplands, much of which are Crown Lands, are essential parts of many island water r

e Many areas on Bowen Island n r

supply watersheds. We also need to protect our valley aquifers which underlie much u

T are groundwater protection areas.

.

of the developed area of Bowen Island. In this regard, many of us live on our water B supply. It is extremely difficult to clean a contaminated aquifer. So we all need to use best practices to ensure we don't contaminate our underground water supplies.

community water supply disinfection filtration

watershed source water protection

groundwater drinking Ensuring a source water protection treatment safe water household water supply treatment

How is your water protected? Water treatment

Protecting water quality in source areas is our first line of defense. Beyond that, community water systems use disinfection (chlorination, ultraviolet radiation) to kill bacteria, viruses, and Giardia cysts, and filtration to remove turbidity that interferes with the sterilization process. Some homeowners on wells treat water to remove dissolved minerals such as calcium (hardness), iron, manganese, or arsenic.

23 Living with summer drought: Ideas for conserving water Raindrop says: Enjoy a golden lawn during the summer drought. r r e e n n r r u u T T

. . B B r e

n Low water at Josephine Lake, r u T

September, 2002 .

B Thirsty lawns and gardens

Outdoor water use, primarily gardening, Why should we conserve water? increases Vancouver's water use by 30% during the summer. Lawns are incredibly So our neighbours and ourselves don't run thirsty, using four times as much as anything short. So we don't deplete our groundwater else in the garden. But this need not be. storage. So stream, lake, and wetland There are many beautiful gardens of native, water levels aren't lowered unnecessarily, drought-tolerant plants. Sprinklers can be Rooftop rainwater: damaging their ecosystems. Because it replaced by efficient drip systems. saves us money. And because being the untapped resource wasteful is irresponsible. An average house roof on Bowen (1200 square foot area) rooftop will yield 160,000 litres or 35,000 catchment gallons of water a year. Many homes on Bowen store rainwater in cisterns or tanks for use in the garden. Some even ultra water efficient use rainwater for shower heads low-flush toilet drip ? all their needs. irrigation Could treated in garden "greywater" from bathwater and washing non-treated water be used in the water rain barrel efficient garden? storage appliances for garden untreated drought water resistant line native plants water wise gardening 4 3 67 8 with drought resistant plants household rain water use septic tank septic field water meter measures use and encourages conservation

treated potable water supply cistern storage water (for drinking only) of rain water line

The leak detective - the water meter

Installing a water meter is the fastest way to detect leaks. A leaking toilet can waste 90 gallons (400 litres) a day.

24 potable water That was an expensive flush! required Treating water to meet drinking water standards can be very expensive. Yet only 10% of our average household water use requires potable water for drinking, food preparation, and kitchen washing. We use this expensive treated water to flush toilets, water our gardens, wash the car, even fight fires!

potable potable water water optional not required

Miserly toilets

Ultra-low flush toilets r e

decrease water use by n r u T

40%! That really saves . on the water bill. B

plant water loss water-wise water use gardening

reservoir

well septic field ocean

recharges ground water system

Septic fields recharge groundwater storage

Most water used by households with septic fields returns to the groundwater system. We use the water, but we return it to the earth. This is good management. In contrast, sewer systems export water to ocean, depleting groundwater storage.

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