Water, Water, Everywhere?

Is It Really So?

Introduction

Richard Boase, P.Geo., CCEPEnvironmental Protection OfficerNorth Vancouver District355 W Queens Rd.North Vancouver, B.C., V7N 4N5Tel (604) 990-2365Email rboase@dnv.org

Introduction

Urban Hydrology

Hydrological CycleImportance of near surface groundwaterInfluencing the hydrological cycle

Introduction

Urban Hydrology Around the Home

Design ideasLandscaping ideasPlant and soil ideasOperation & Maintenance

Introduction

Future Considerations

Climate ChangePolicy & BylawsTrends

Urban Hydrology

Hydrological CycleThe process by which water, in liquid, solid and gaseous states, is cycled through the ecosystem within the hydrosphere

Condensation

PrecipitationTranspiration

Evaporation

Groundwater flow

PercolationStream flow

Hydrological Cycle

Urban Hydrology

Near Surface Base flow

Importance of near surface groundwater

Urban Hydrology

Time

Flow

Influencing the hydrological cycle

Poor sediment & water quality

High sediment loads

Reduced coverReduced complexity

Increased bank erosion

Influencing the Hydrological Cycle

Urban Hydrology around the Home

Urban Hydrology around the Home

The single largest factor we can control, and make a difference with, is the

landscaping in our yards.

Part of the problem

Part of the solution

Urban Hydrology around the Home

www.waterbalanc

74% 71%

21% 23%

4 % 6%

0

2 0

4 0

6 0

8 0

1 0 0

Pe

rce

nt

of

To

tal

An

nR

ain

fall

L e s s th a n 5 0 % o fM A R

5 0 % o f M A R to M A R G re a te r th a n M A R

R a in fa ll E v e n t S iz e (m m )

T y p ic a l V o lu m e D is tr ib u tio n o f A n n u a l R a in fa l l

S o u th C o a s t (B u rn a b y M o u n ta in ) O k a n a g a n (K e lo w n a A irp o rt)

N ote : B urnaby M oun ta in M A R * = 7 0 m m K e low na M A R * = 20 m m (*2 4 -h o u r ra in fa ll )

20%Large Storms

75%Small Storms

5%Extreme Storms

RAINFALL SPECTRUM

SITE

Infiltrate or Harvest Small Storms at the Source to Reduce

Total Runoff Volume

Provide Storage to Control the Rate of Runoff from Large Storms

WATERSHED

Ensure that the Downstream Systemcan Safely Convey

Extreme Storms

NEIGHBOURHOOD

LIGHTSHOWERS

HEAVY RAIN

EXTREME STORMS

KEEP RAIN ON SITE

DELAY THE RUNOFF

REDUCE FLOODING

INTEGRATED STRATEGY

LIGHT HEAVY EXTREME

The Design Objective is to Infiltrate the First 30mm of Rainfall

Design Ideas

How the Water Balance Model can help improve our landscape

• Ask questions & get answers• Spend your time & money wisely• A free resource• Brings design people together

Design Ideas

Typical SFD lotNo BMP

1630 m3 runoff

Same lot with Rain Garden

1083 m3 runoff

Design Ideas

• Think NATURAL (Hydrological Cycle)

Standard Sump

Exfiltration Sump

700 square foot garage

No storm connection at rear of property

Condition of permit

Design Ideas

Landscaping Ideas

• Think of cascading systems

Practical Site Level Solutionsare Typically Landscape-based

Plant & Soil Ideas

Absorptive Landscapes

Up to 50% less runoff

Less water

Less chemicals

Plant & Soil Ideas

Compost and amended soils

•GVRD produces about “biosolids” 70,000 tonne/yr

•Used in mine reclamation, ranchland enrichment, silviculture and landscaping

•Restores poor or depleted soil with nutrients and organic matter

•20%biosolids, 20% yard compost, 20% wood shavings, 40% sand

•Use a minimum 300 mm depth amended soil

Plant & Soil Ideas

Compost and amended soils

• Adsorb more water, less run off

•Less weeds, less fertilizer, less competition for water

•Deeper root systems, healthier lawns

Plant & Soil Ideas

Plant & Soil Ideas

• Native species have adapted to our climate making them a (personal) first choice

• Asses your yard for wet areas, sandy areas, light areas then chose plants

Future Considerations

Climate change

Policy & Bylaws

Trends

Future Considerations

Future ConsiderationsTemperature rise

More rain

Sea level rise

Water Resources

Supply

Quality

Competition

Forest impact

Composition

Range

Health & Productivity

Loss of species

Lower biodiversity

Less habitat

Future Considerations

The City of Courtenay was thefirst municipality to adopt a Minimum Soil Depth Policy

Trends

More Local Governments adopting rain barrel programs

Burnaby, Coquitlam, Delta, Langley City, Langley Township, Vancouver all have some form of rain barrel program

Trends

Natural Lawn Care

Composting & Mulching

Organic Gardening

Water wise gardening

Biological pest control

In Closing70% of our water reserve falls in autumn & winter

Highest demand falls in July, typically we’ll use 35% more water in July than December

Average consumption is 1x107 L/day this can double on a hot summer day

Even a poor lawn only requires 2.5cm water once a week

Water early in the am, use sprinklers that produce drops rather than spray, water ONLY your lawn

Plants need more water than grass use a watering can

Aerate and add compost to your lawn

In Closing

Thanks to Liz Haan and the BC Master Gardener’s Assoc.