GEOG 3000 Resource Management Managing and Conserving Supplies

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GEOG 3000 Resource ManagementManaging and
Conserving Supplies

• M.D. Lee CSU Hayward Winter 2004

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Famines and Feasts

• As explained in CRO Sections 10.2 and 10.3,
  water can be a problem either because it is too
  plentiful (floods) or insufficient (droughts and
  demand-induced shortages).
• Floods have predominantly been controlled by
  engineering designed to increase streamflow
  capacity, bypass sensitive areas or store peak
  flows behind dams for slow release.
• Increasingly, sophisticated forecasting and
  monitoring systems are used to plan dam
  operations and/or emergency responses.
• Damming and canalizing are gradually giving way
  to watershed management and soft engineering
  (allowing selective flooding and relocation of
  at-risk urbanization).
• Federal flood aid frequently promotes rebuilding
  however.
• Dams and flood controls have ecological
  side-effects.

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Water shortages

• New water supplies will be developed over the
  coming decades including more groundwater
  exploitation, desalinization of brackish/sea
  water, and more inter-basin transfers (have you
  heard about the controversy over giant
  zip-locks!).
• However, an increasing push will come in the area
  of water conservation, given the relative
  inefficiency with which we use water at present.
• The objective of water conservation is the
  cost-effective reduction of the water demanded
  for a specific purpose down to the minimum volume
  or flow-rate necessary to satisfy the needs of
  the water user.

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How to get more from our water?

• Technical changes - suites of urban conservation
  measures, more intensive agriculture/irrigation,
  recycling of wastewater.
• Economic forces - calculate and charge the true
  cost of water to users, create a free market for
  water, transfer water to the highest and most
  beneficial uses.

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Getting more from our water.

• Political measures - draft new laws and codes to
  gradually bring about or more quickly enforce
  efficient use and conservation in a variety of
  areas.
• Social tools - education/behavioral change,
  changes in land use policies and practices,
  population control, and so forth.
• ALL OF THE ABOVE!

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Achieving conservation goals

• We can seek to change water using habits -
  requires continuous participation by water users
  to achieve conservation, and/or
• We can seek to change water using technology -
  requires installation of new technology to
  achieve conservation.
• BOTH OF THE ABOVE!
• A key step in water conservation is the audit - a
  systematic analysis of all water use practices to
  establish a water balance, followed by a
  cost-benefit analysis designed to identify the
  most appropriate behavior/technology options.
• We can conduct farm audits, landscape audits,
  household audits, facilities audits any size
  and scale.

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Major urban gains come from...

• Water meters - so people can know how much they
  are using, pay by actual volume used, and track
  conservation.
• Implementing inclining rate structures - the more
  you use the proportionally more you pay.
• Installing low-flush toilets - the singular most
  effective measure for interior water use
  reductions - 77 reduction.
• Eliminate single-pass cooling washing systems -
  install recirculating systems for buildings and
  industry.
• Identifying and fixing visible and hidden leaks
  quickly and effectively - leak detection is a
  must.
• Requiring xeriscape and low-flow irrigation -
  native plants, rational use of turfgrass, and
  water efficient irrigation equipment are key.
• Substituting reclaimed water for fresh.

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Major agriculture gains come from.

• Lining and covering irrigation canals and ditches
  - evaporation and seepage losses are
  considerable.
• Switching to more efficient irrigation - from
  furrow/flood to sprinkler systems to drip lines.
• Recovering irrigation runoff - often farmers
  over-water and return flows can be captured and
  pumped back to the field inlet for reuse.
• Laser leveling of fields - to create pinpoint
  water distribution accuracy and uniform watering.
• Adoption of crop moisture balances - using daily
  potential evapotranspiration, rainfall and/or
  soil moisture sensors.
• Developing drought and salt resistant crop
  varieties.
• Using reclaimed wastewater - still some issues
  here to deal with.