California Water Issues and Wetlands

Good sources: aquifornia.com

http://www.water-ed.org/watersources/default.asp

Figure 1. Freshwater Consumption as a Percentage of Local Average Annual Precipitation. (Source: USDA-NRCS, 2001)

California’s Water Supply Ground Water

Provides 20-30% of state’s water (up to 40% in dry years)

Aquifers hold ~20X the amount of water behind the >1200 dams in the state

Surface Water Average annual precipitation = 24 inches (ranges

from close to zero in deserts to >100 inches in northern mountains) falls mostly in winter, needed in summer

60% evaporates or transpires returns to atmosphere; percolates into soil

Also receive water from Colorado River and Oregon rivers

California Water Supply California has been called “the most

hydrologically altered landmass on the planet”

We’ve transformed deserts into farmland and supported the development of large cities and towns

E.g. “Inland Empire” 70 percent of California’s runoff occurs

north of Sacramento; 75 percent of California’s urban and agricultural demands are to the south

Moving the water uses LOTS of energy The State Water Project is the largest

single user of energy in California Also lose water in process

Santa Clara County Water Supply

Less than half comes from local sources - aquifers

The rest is imported from the Sierra Nevada throughpumping stations in the Sacramento-San Joaquin River Delta

California Water Use

Agriculture is the largest use of California water supply

California is the largest producer of food and agriculture in the US

Droughts leads to mandatory water reductions (last year - 30%) pay penalty for non-compliance Lose crops Trees stop fruiting

Also need water for domestic and industrial uses AND environment

Sacramento-San Joaquin River Delta

2/3 of CA population and 2.5 million acres of farmland depend on the Delta for water

Consists of series of levees to protect land, which is below sea level, from floods and high tides

Water also pumped to central and southern CA

If the Delta’s levees were damaged due to heavy flooding or an earthquake, the state likely would not have the water to meet the public’s needs

Wildlife threatened by water shortages – Endangered Delta Smelt and salmon less water diverted to cities and agriculture

Current Conditions - CA

Water systems have not been upgraded since the ‘70s

Population has increased by ~14 million people expected to increase 56% by 2050!

Straining existing water supplies Drought and climate change also

reducing snowpack runoff replenishes our aquifers, fills our reservoirs, and drains to the Delta

Colorado River also increasingly stressed must share water resources! 2009

Current Conditions - Bay Area Experienced three consecutive year of

drought This year rainfall is “normal”, but

reservoirs still low Last year reservoirs were at lowest

levels since 1992 at 65% capacity in county; now at 73% capacity

Last year water district called for 15% mandatory reduction in water use – still in effect

How that is enforced depends on local water retailers Some retailers put restrictions on watering lawns and increases in water rates City of San Jose price of water dependent on how much you use

CA Water Video

Solutions

Urban water conservation

Agricultural water conservation

Increase surface storage areas - dams and reservoirs

Desalination Capture and retain

storm water and urban runoff

Recycle water

What is a Wetland?

Areas where groundwater is at or near the surface long enough to support water plants

Transition between terrestrial and aquatic zones

Considered the most biologically diverse of all ecosystems

Types of Wetlands

Freshwater Bogs, marshes, swamps, sloughs

Saline (Salty) Salt marsh, tidal wetlands, tidal sloughs

Importance of Wetlands

Flood control Filter water Recharge aquifers Prevent soil erosion Remove and store greenhouse gases Supports high biodiversity

Loss of Wetlands

Early 1600’s 220 million acres in US >50% have been destroyed 1950-1970 - ~59 million acres lost 91% lost in CA

http://www4.ncsu.edu/~tkwak/marsh.html

Wetland Loss and HurricanesKatrina Example

New Orleans in floodplain of Mississippi River inevitably floods Built elaborate system of levees to prevent flooding of communities

from river Increases risk of flooding from ocean storms in the process Wetlands provide first line of defense against hurricanes

Limit storms' access to the warm open ocean water that drives them

Create a physical barrier to the floodwaters Lack of river flooding = less sediment and nutrients to wetlands Coastal wetlands are deteriorating and shrinking makes ocean

communities exposed and vulnerable Witnessed consequences in Hurricane Katrina

Katrina Video

Wetland Conservation

SF Bay Salt Marsh Video Santa Clara Valley Freshwater Wetlands V

ideo