Water Quality & Quantity Issues For Turfgrasses In Urban Landscapes

Urban Perennial Grasses In Times of a Water Crisis: Benefits and Concerns

Dr. Mike Kenna

US Golf Association

Water Quality and Quantity Issues for Turfgrasses in Urban Landscapes

3-Day Workshop held January 23-25, 2006 in Las Vegas, NevadaHosted by The Council for Agricultural Science and Technology (CAST)Opportunity to discuss issues facing the turfgrass and water industries

COLRCAST

Water Quality and Quantity Issues for Turfgrasses in Urban Landscapes

25 ScientistsCo-chaired by Dr. James Beard, Texas A&M University and Dr. Mike Kenna, USGALinda Chimenti, Managing Scientific Editor, CASTOne free copy to all current CAST members

What�s the Problem?

Proponents:Environmental and human benefitsDecreased runoff from storm eventsErosion and pollution controlHeat dissipationRecreational and business opportunitiesEnhanced property values

Critics:Use excessive waterRequire unnecessary pesticides and fertilizersDisturb existing land-use patternsWaste time, money and Resources

Population � Areas of Growth

U.S. Precipitation

U.S. Freshwater Withdrawals, 2000

Converging: Population GrowthLimited Water SuppliesHigh Water-Use Rates

Pending Water CrisisRapidly expanding population, specifically in areas of limited or unreliable water resources

Growing economy with new home construction and business development

Potential shift of environmental conditions for plants and animals that rely on water used by humans

Landscape plant water requirements Social and cultural aspects associated with the availability of clean, fresh water

Understanding �Peak Demand�

Addressing �Peak Demand�

Landscape-Created Peak DemandHigh-demand peak of a short duration

System response issuesResource Supply and AvailabilityStorage and TreatmentDistribution

Calls for Conservation

Turf Restrictions Result

Water PolicyOur drinking water system is extremely decentralized

Local government ownershipIndependent government authority ownershipPrivately owned companiesPublic-private partnerships

Environmental Protection AgencyClean Water ActSafe Drinking Water ActPrevent pollution and decrease risk to humans and ecosystemsIntegrated federal, state, and local implementationPositive impact on water protection and conservation

Water Use and ConservationSelect correct turfgrass for the climateProper landscape designDevelop sustainable water management plans

Development of Native Species

Limited water, poor quality water, poor soils

Deep root system reaching 8 feet when mowed at 2.5 inches (4x KBG)

Improve Adaptation of Major Turf Species

Improve Adaptation of Major Turf Species

Specific Cultural PracticesMowing height and frequencyTurfgrass nutritionTurfgrass irrigationSoil cultivationTopdressingWetting agentsPlant growth regulatorsPest management

Irrigation Efficiency

Rain sensorsLicensed Irrigation Designers Yearly system reviewDesigns reviewed and work inspectedRebate for design changes

San Antonio, TX - Seasonal Irrigation Program (SIP) Brochure

Seasonal Irrigation Program (SIP)Based on PET related to four years of studiesSimple program � One weather stationTexas Cooperative ExtensionNewspaper, radio, e-mail, hotline, and phone messageRecommendation based on turf typeMaster Gardener�s and Gardening Volunteers sign folks up5,000 signed up, 20% savings realized

Water Conservation OrdinancePassed In January, 2005

Unanimous vote with support of turfgrass industry new home builders, car washes, irrigators

Landscapes on new homesFour inches of soil under turfZoned irrigationTurf varieties survive 60 days drought

Rain Sensors

Drought Restrictions and EnforcementDesigned to reduce water use, but preserve lawnMain restrictions � Water lawn one day/week based on addressSaved 14.9% over six months in 2000Stage three (3), water every two weeksFive part-time police officers cite violators with misdemeanor ticket

Gallons Per Capita Per Day

SAWS Service area has grown by 300,000 since early 90�s, but no new water used.

Reclaimed WaterIncreased usage by golf coursesHigher turfgrass growth ratesMinimal downward movement of nutrients

Using Recycled or Brackish WaterEfficient and uniform water application

Filtration of suspended matter

Groundwater quality monitoring programs may be required

Protect adjacent properties or bodies of water from irrigation runoff or overspray.

Pesticide and Nutrient FateThe research shows that undermost conditions, the small amounts of pesticides and nutrients that move through the soil are found at levels below the health and safety standards established by the U.S. EPA

Thatch layer in a typical turfgrass

1.14 m (3.75 ft) diameter

Monolith Lysimeters

Constructed between 1989-19911.20 m (4 ft)

Nitrogen Leaching � 1998 to 2005

Year

98 99 00 01 02 03 04 05 06

mg/

L

0

10

20

30

40

50

60

Low N R ate H igh N R ate

RunoffClimate

temperature, evapotranspiration, and volume, intensity, and duration of precipitation

Site and Soil Conditionssoil texture and organic matter content, bulk density, hydraulic conductivity, thatch layer presence, landscape slope, and proximity to water resources

Managementirrigation, drainage, fertilizer and pesticide application, and cultural practices.

Nitrogen Runoff Rate

0

0.2

0.4

0.6

0.8

1

1.2

0 10 20 30 40 50 60 70 80 90

Time After Initial Runoff (min)

N lo

ss (%

of a

pplie

d/m

in )

.

Small plotsLarge plotsTime * Plot size Pr > F = 0.003

Phosphorus Runoff Rate

0

0.2

0.4

0.6

0.8

1

1.2

0 10 20 30 40 50 60 70 80 90

Time After Initial Runoff (min)

P lo

ss (%

of a

pplie

d/m

in)

.

Small PlotsLarge Plots

Time * Plot size Pr > F = 0.037

0 10 20 30 40

1E-3

0.01

0.1

1

10

100

1000

Lo

g - R

eser

voir

Con

cent

ratio

n (u

g/L)

Compounds - Sorted high to low

USGS Monitoring Results Acute (Peak) Model predictions

Tier I Model Predictions vs. Monitoring

Maximum Measured Value from Study

EPA PRZM-EXAMS Scenarios vs. Monitoring

Tiphia wasp lays egg on masked chafer grub.

Insect Biological control

Host Plant Resistance

Comprehensive Approaches - BMPsScience-basedIncorporates all strategies in the ecosystem Embodies all stakeholders and their social, economic, and environmental concernsValues education and communication outreachAllows integration of new technologies and conceptsApplied at the regulatory, watershed, community, and site-specific levels, as well as in educational realmsMaintains flexibility to adjust to new situations.

Benefits of BMPs modelMove forward in a positive and unified manner

Excellent environmental modelDemonstrates a high degree of environmental stewardship

Provides for research, education, and extension needs to serve the turfgrass industry and society

Environmental Management SystemsConsiders all environmental issues and consequences on a site

Includes economic consequences and potential adverse effects

Assessment of economic or investment concern whenever peak demand becomes a driving force in decisions about providing water to the public

The tendency is to use a simplistic approach for eliminating certain water uses by enacting public laws. A single- issue approach, however, can lead to other potentially serious problems.

Water issues need to be addressed:In an integrated manner

Fiscal realities facing the nation need to be recognized in order to effectively coordinate the actions of federal, state, tribal, and local governments

Perceived environmental problems must not be addressed in isolation, but in terms of all the interrelationships and stakeholders associated with these landscapes

The ultimate goal is to provide quality urban areas for activities and recreation while conserving and protecting our water supply.

Questions and Discussion?