2 Water Resources Water Earth’s surface is covered by 71% water Essential for life – can survive only a few days without water
3 Supply of Water Resources Small fraction (.014%) is readilyavailable for human use
4 Evaporation and transpiration Water Cycle – continuously collected, purified, recycled and distributedEvaporation and transpirationEvaporationStreamInfiltrationWater tableUnconfined aquiferConfined aquiferLakeWell requiring a pumpFlowingartesian wellRunoffPrecipitationConfinedRecharge AreaAquiferLess permeable materialsuch as clayConfirming permeable rock layer
5 WatershedA watershed describes the total area contributing drainage to a stream or riverMay be applied to many scalesA large watershed is made up of many small watersheds
8 Evaporation and transpiration StreamInfiltrationWater tableUnconfined aquiferConfined aquiferLakeWell requiring a pumpFlowingartesian wellRunoffPrecipitationConfinedRecharge AreaAquiferLess permeable materialsuch as clayConfirming permeable rock layerZone of saturation(spaces completely filled with water)
9 Water sourcesSurface runoff – 2/3 lost to floods and not available for human use.Reliable runoff = one thirdAmount of runoff that we can count on year to yearGroundwaterZone of saturationWater table – top of zone of saturationAquifer – water saturated layers of sand, gravel or bedrock through which groundwater flows.Recharge slow ~ 1 meter per year
10 Use of Water ResourcesHumans directly or indirectly use about 54% of reliable runoffWithdraw 34% of reliable runoff for:Agriculture – 70%Industry – 20%Domestic – 10%Leave 20% of runoff in streams for human use:transport goods, dilute pollution, sustain fisheriesCould use up to 70-90% of the reliable runoff by 2025
11 Too Little Water Problems in the West Dry climate Drought Desiccation Acute shortageAdequate supplyShortageMetropolitan regions with population greater than 1 millionUS has plenty of water.Much of it is in the wrongplace at the wrong time.Most serious problems areflooding, pollution,occassional urban shortages
12 Water conflicts: Western US Highly likely conflict potentialSubstantial conflict potentialModerate conflict potentialUnmet rural water needsWash.OregonIdahoNevadaCaliforniaUtahMontanaWyomingColo.N.M.N.D.S.D.Neb.KansasOak.TexasWater andFish
13 Water conflicts: Global Two main factors for water shortage: dry climate and toomany people. Many people live in hydro poverty – can’t afford cleanwater.
14 Too Much Water: Floods Natural phenomena Aggravated by human activitiesRain on snow Living on floodplainsImpervious surfacesRemoval of vegetationDraining wetlandsFloodplainLeveeFloodwallDamReservoir
16 Using Dams and Reservoirs to Supply More Water: The Trade-offs Large lossesof water throughevaporationFlooded land destroys forests or cropland anddisplaces peopleDownstream flooding is reducedDownstream cropland andestuaries are deprived ofnutrient-rich siltReservoir is useful for recreation and fishingCan produce cheap electricity (hydropower)Migration and spawning of some fish are disruptedProvides waterfor year-roundirrigation ofcropland
17 Tapping Groundwater Year-round use No evaporation losses Often less expensivePotential Problems:Water table lowering – too much useDepletion – U.S. groundwater being withdrawn at 4X its replacement rateSaltwater intrusion – near coastal areasChemical contaminationReduced stream flows
20 Solutions Sustainable Water Use Not depleting aquifersPreserving ecological health of aquatic systemsPreserving water qualityIntegrated watershed managementAgreements among regions and countries sharing surface water resourcesOutside party mediation of water disputes between nationsMarketing of water rightsRaising water pricesWasting less waterDecreasing government subsides for supplying waterIncreasing government subsides for reducing water wasteSlowing population growth
21 Pollution Source terminology Point source = pollution comes from single, fixed, often large identifiable sourcessmoke stacksdischarge drainstanker spillsNon-point source = pollution comes from dispersed sourcesagricultural runoffstreet runoff
22 Types of Water Pollution from Table 9-1 p. 187 Sedimentlogging, roadbuilding, erosionOxygen-demanding wasteshuman waste, storm sewers, runoff from agriculture, grazing and logging, many othersNutrient enrichment = EutrophicationN, P from fertilizers, detergentsleads to increased growth in aquatic systems, ultimately more non-living organic matter
23 BODAs micro-organisms decompose (through respiration) organic matter, they use up all the available oxygen.Biological Oxygen Demand (BOD) Amount of oxygen required to decay a certain amount of organic matter.If too much organic matter is added, the available oxygen supplies will be used up.
25 EutrophicationEutrophic – well-fed, high nutrient levels present in a lake or riverOligotrophic – poorly-fed, low nutrient levelsWater bodies can be naturally eutrophic or oligotrophic, but can also be human-caused
26 Types of Water Pollution (con’t) from Table 9-1 p. 187 Disease-causing organismsfrom untreated sewage, runoff from feed lotsToxic chemicalspesticides, fertilizers, industrial chemicalsHeavy metalslead, mercuryAcids (to discuss later)Elevated temperatures = Thermal Pollutionwater is used for cooling purposes, then heated water is returned to its original sourceany increase in temperature, even a few degrees, may significantly alter some aquatic ecosystems.
28 Oil SpillsExxon Valdez released 42 million liters of oil in Prince William Sound, contaminating 1500 km of Alaska coastline in 1989Was the cleanup effective?Most marine oil pollution comes from non-point sources:runoff from streetsimproper disposal of used oildischarge of oil-contaminated ballast water from tankers
29 Growth of populationSupply & demand are in growing conflict – supply is finite – water management driven by values and needsIncreases demand/use of waterIncreases land use and changes vegetation and permeabilityIncreases demand for instream values – instream flows are for people
30 The construction of dams have slowed the once flowing ColumbiaRiver into a series of lakes.
31 Agriculture uses approximately 70% of the water withdrawn from our streams and rivers
32 Changing land use changes vegetation and need for water
34 Areas with 15 to 75 percent impervious surface are characterized as moderately developed. Areas with greater than 75 percent impervious surface are considered urban or highly developed. Areas with greater than 10% impervious surface have been proven to have a negative affect on groundwater and stormwater.
35 Water Rights Water collectively belongs to the public Cannot be owned by individualsIndividuals or groups may be granted rights to use waterLegal authorization to use a predefined quantity of public water for a designated purpose.Irrigation, domestic water supply, power generation
36 Water RightsState law requires certain users of public waters to receive approval from the state prior to using water.Any use of surface water which began after 1917 requires a water-right permit.Withdrawals of underground water from 1945 requires a water-right permit.
38 Instream flowsResult – the more we know about stream ecology, the more we realize that all the water has instream value, meaning there is no surplusCompromises and minimizing impact – thresholds for rate of impactOther ways to achieve ecosystem goals – wider view, not just flows – watershed land management
39 Legal/political aspects of instream flow provide a flow of water sufficient to adequately support food fish and game fish populations in the stream (RCW )provide protection and preservation and where possible enhancement, of wildlife, fish, … and other environmental values … (RCW 90.54)protect fish, game, birds, and other wildlife, recreational and aesthetic values and water quality (RCW 90.22)antidegradation requirements of Washington’s water quality standards (Ch A WAC, following Federal Clean Water Act)
40 Instream flowsOther ways to achieve ecosystem goals – wider view, not just flows – watershed land managementAvoid headwater disturbanceVegetationGeology and topographyMaintain longitudinal and lateral connectivityAvoid mainstem in-channel storageAllow floodplain to function as floodplain
41 Avoid headwater disturbance and leave vegetation
47 Flow restoration Markets and transfers Need to protect restored flows Enforcement
48 Opportunities Parks and wilderness areas Renewable natural resource management and harvest (forestry, grazing, secondary forest products)Municipal watershed protectionLow intensity sustainable agriculture
49 Watershed PlanningThe 1998 legislature passed ESHB 2514, codified into Ch RCW, to set a framework for developing local solutions to watershed issues on a watershed basis. Ch RCW states: The legislature finds that the local development of watershed plans for managing water resources and for protecting existing water rights is vital to both state and local interests.
50 Watershed Planning RCW 90.82.005 Purpose. The purpose of this chapter is to developa more thorough and cooperative method ofdetermining what the current water resourcesituation is in each water resource inventory area of thestate and to provide local citizens with the maximumpossible input concerning their goals and objectives forwater resource management and development.
51 Watershed PlanningEach implementation plan must contain strategies to provide sufficient water for: (a) Production agriculture; (b) commercial, industrial, and residential use; and (c) instream flows. Each implementation plan must contain timelines to achieve these strategies and interim milestones to measure progress