too much water

1. Too Much WaterToo Much Water

2. TOO MUCH WATERTOO MUCH WATER
 FloodingFlooding – water overflowing normal– water overflowing normal
channel spilling into adjacent areachannel spilling into adjacent area
 Caused by:Caused by:

Heavy rainfallHeavy rainfall

Rapid snowmeltRapid snowmelt

Removal of vegetationRemoval of vegetation

Destruction of wetlandsDestruction of wetlands

3. TOO MUCH WATERTOO MUCH WATER
 Benefits of flooding:Benefits of flooding:

Productive farmland from nutrient-rich siltProductive farmland from nutrient-rich silt

Recharge groundwaterRecharge groundwater

Refill wetlandsRefill wetlands
 Costs of flooding:Costs of flooding:

Kill peopleKill people

Destroy propertyDestroy property

4. TOO MUCH WATERTOO MUCH WATER
 FloodplainsFloodplains – area into which floodwaters– area into which floodwaters
spill – usually have wetlands – providespill – usually have wetlands – provide
natural flood and erosion control, maintainnatural flood and erosion control, maintain
high water quality and recharge groundwaterhigh water quality and recharge groundwater

People live here for fertile soil, flat land, proximityPeople live here for fertile soil, flat land, proximity
to river – water, transportation, recreationto river – water, transportation, recreation

5. TOO MUCH WATERTOO MUCH WATER
 To minimize floods, rivers have beenTo minimize floods, rivers have been
narrowed and straightened (narrowed and straightened (channelizedchannelized))
withwith leveeslevees andand dikesdikes and dammed to storeand dammed to store

Ex: Kissemmee River in EvergladesEx: Kissemmee River in Everglades

7. TOO MUCH WATERTOO MUCH WATER
 Levees only works up to a pointLevees only works up to a point

8. TOO MUCH WATERTOO MUCH WATER
 Comparison of Mississippi River at St. Louis,Comparison of Mississippi River at St. Louis,
Missouri under normal conditions (1988) andMissouri under normal conditions (1988) and
after severe flooding (1993)after severe flooding (1993)

9. TOO MUCH WATERTOO MUCH WATER
 Human activities – removal of vegetation andHuman activities – removal of vegetation and
paving – have contributed to increasedpaving – have contributed to increased
floodingflooding

11. TOO MUCH WATERTOO MUCH WATER
 Mangroves can protect land from floodingMangroves can protect land from flooding
damage from tsunamisdamage from tsunamis

12. TOO MUCH WATERTOO MUCH WATER
 Draining, filling and building on wetlands canDraining, filling and building on wetlands can
lead to floodinglead to flooding

13. TOO MUCH WATERTOO MUCH WATER
 Flooding will increase as sea level rises due toFlooding will increase as sea level rises due to
global climate changeglobal climate change

14. Case Study: BangladeshCase Study: Bangladesh
 Densely populated,Densely populated,
poverty, at sea level onpoverty, at sea level on
coastal floodplaincoastal floodplain
 Monsoon flooding is criticalMonsoon flooding is critical
for agriculturefor agriculture
 Big floods are moreBig floods are more
common due to poorcommon due to poor
practices in Himalayas,practices in Himalayas,
also storms and tsunamisalso storms and tsunamis

15. Fig. 14-24, p. 331
Solutions
Reducing Flood Damage
Prevention Control
Preserve forests on
watersheds
Strengthen and
deepen streams
(channelization)Preserve and
restore wetlands
in floodplains
Tax all development
on floodplains
Build levees or
floodwalls along
streamsUse floodplains
primarily for
recharging aquifers,
sustainable
agriculture and
forestry, and
recreation Build dams
Think about where
we live

16. U.S. Federal Flood Insurance ProgramU.S. Federal Flood Insurance Program
 Low-cost, federally backed insuranceLow-cost, federally backed insurance
 Low interest rates for rebuildingLow interest rates for rebuilding
 Tax-payer subsidies, but political resistance toTax-payer subsidies, but political resistance to
endingending

17. U.S. Federal Flood Insurance ProgramU.S. Federal Flood Insurance Program

18. SOLUTIONS: USINGSOLUTIONS: USING
WATER MOREWATER MORE
SUSTAINABLYSUSTAINABLY
 We can use water moreWe can use water more
sustainably by cuttingsustainably by cutting
waste, raising waterwaste, raising water
prices, preservingprices, preserving
forests and wetlands inforests and wetlands in
water basins andwater basins and
slowing populationslowing population
growthgrowth