Sources of Water that enter Rivers/Streams
    groundwater: rainfall or snowmelt soaks into earth, saturating the ground
        rainfall varies a lot in WA:  90 in/yr in Forks, 36 in Seattle, 8 in Yakima
            low groundwater recharge of lakes and streams in summer when no rainfall
    overland flow: runoff directly into stream overland, soil must be saturated first
        not very common, only during heavy rainfall season
    glacial melt:  melting throughout year; most places on Earth have no glaciers
        glaciers very important in WA: provide streamflow during summer drought

River/Stream Channel:  trough shaped depression that holds running surface water
    parts of channel:  bed/bottom of river, banks/edges of channel, flood plain on sides
        channel and adjacent areas called riparian corridor, critical habitat, high biodiv.
    size of river/channel measured by width across and average depth of water
        average width x depth = cross sectional area through channel
    speed/velocity of water; velocity and roughness, velocity and depth

    Discharge = volume of water passing by a point per time = width x depth x velocity
        can't measure discharge directly so measure cross sectional area and velocity
        units of discharge:  gallons/min (gpm), m3/sec, acre-feet/day or year
             ex:  mouth of Columbia River, 180 million acre-feet/year

Transport of Sediment aka "Load":  rivers carry 3 different types of sediment/load
    Dissolved Load:  ions carried in solution; invisible.  "fresh" water has plenty of ions.
        ions end up in oceans, concentrated there.
    Suspended Load:  mud carried in suspension.  mud of flood plains--deltas--ocean.
    Bed/Bottom Load: gravel and sand carried along the bottom/bed, mostly during floods
      large bits can't be carried, so must be rolled, bounced or slid along river bottom

Flooding and Flood Plain:  the river's way of dealing with too much water for the channel
    flood plain:  flat areas adjacent to stream that are flooded periodically
    flooding frequency: about every 2-3 years for most streams, floods not a rare event
    flood plains affect the width, average depth and average velocity of stream
        ave. depth and velocity decrease during flooding, width increases dramatically
    deposition of suspended sediment to form flood plains; terraces & ancient flood plains
    flood plains are Nature's way of taking care of extreme discharges

River Deposition: landforms produced from constantly shifting river deposits
     sand and gravel bars; point bars at meanders, mid-channel bars, braided streams
        some engineers believe that constant dredging of streams will provide more channel space for flood waters;
        but river will immediately deposit sediment to fill in the channel to its equilibrium value
    meander bends: deposition on the inside (point bar), erosion on the outside (cutbank)
    channels are constantly migrating from side to side, sweeping across the valley
    there is NO spot in the river valley safe from river erosion on the long term
    terraces: ancient flood plains.  Ancient glacial streams and flood plains in Washington
        how do you tell a terrace from a flood plain?  important practical question
            different building codes, insurance requirements, etc. etc. depending upon which it is.
 

Uses of Water in Rivers and Streams:  Offstream and Instream Uses
    Offstream/Diverted:  water taken from stream/river, transported some distance
        ex:  public water supplies, irrigation, etc.
    Instream:  water left in channel
        ex:  fish and wildlife habitat, hydroelectricity generation, recreation, etc.

Uses of Riparian Corridor:  Humanocentric Concerns

    Agriculture: with emphasis on plant crops, less so on livestock
        1.  Irrigation:  crops typically require large quantities of fresh water
            irrigation in PNW uses 10 times water of all other uses combined
                ex:  U. Columbia Basin, about 7000 acre-feet/day surface water withdrawal
        2.  Flood Plains:  one of best agricultural lands on Planet Earth
            flatómuch more time and energy consuming to farm on tilted land
            soilsóextremely rich in nutrients, excellent consistency (loamy)
                naturally replenished every 2 years during floods
            irrigationóready water supply handy, either stream or groundwater
            marketótransportation systems often follow rivers and streams

    Hydroelectric:  provides 90% of electricity in WA state, lowest rates in US
            11 dams on Columbia mainstem in WA/OR, another 4 on Snake in WA
            3 large capacity dams on Skagit (Diablo, Gorge and Ross)
            many other small ones in WA:  Nisqually, Yakima, Cowlitz etc.
    pros:  more or less non-polluting, renewable resource, use same water 10 times
    cons:   complete obliteration of original riparian habitat replaced by reservoirs
         reservoirs = giant evaporators, lose water to environment.  local climate???

    Thermoelectric:  boil water to steam, steam passes over turbine, creates electricity
        3? coal-fired, 1 nuke-fired and 2? garbage-fired power plants in WA
        water used in two ways: 1. steam itself, recycled. 2.  cool steam with cold water

    Industrial:  manufacturing industries often use tremendous amounts of water
        excellent coolant in high temperature manufacturing, good low level solvent

    Municipal Consumption:  water for household use often taken from streams/rivers
        ex:  Seattle, mostly from Cedar River, own whole drainage basin
    drinking, cooking, bathing, waste transport, etc.

    Transportation:  barges still a very important component of shipping industry
        depend on slackwater conditions, often require dams and locks; e.g. Snake River

    Recreation etc.:  gaining more and more recognition

    Real Estate:  flat, easy to build on, scenic etc.  but spawns flood control devices:
        levees and dikes designed to hold flood waters back, many negatives
            prevent replenishing floods, create larger floods downstream, modify habitat

Uses of Riparian Corridor:  Ecosystems, Biomes, Habitat
        discussed previously.  very important biomes on Planet Earth, many varieties
          typically high biodiversity, high biomass, ecological storehouses
          typically linked to/interwoven with many OTHERS e.g. estuaries.
 
 

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