• You will need to login or register before you can post a message. If you already have an Agriville account login by clicking the login icon on the top right corner of the page. If you are a new user you will need to Register.

Announcement

Collapse
No announcement yet.

Collecting water...How to charge "empty" aquifers?...

Collapse
X
Collapse
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Collecting water...How to charge "empty" aquifers?...

    CA Looks to Storms to Fight Drought
    Fri Jan 8, 2016 06:28 AM CST
    SAN DIEGO (AP) -- Much of the torrential rain that fell on Southern California this week flowed right into the ocean, just like it did before the state's epic drought.

    That seemed like a good idea for many years, as storm drains provided a crucial defense against flooding. But with California entering what may be a fifth year of drought, water agencies are slowly moving to capture and store more of this precious resource.

    "That was the 19th, 20th century thinking: 'Let's get that water out of here as fast as possible,'" said Deborah Bloome, senior director of policy at TreePeople, a nonprofit group that is working to increase rain capture in the Los Angeles area.

    Now people are more likely to see a rapidly disappearing flood — nearly 3 inches fell on much of Southern California this week — as a wasted opportunity.

    The State Water Resources Control Board approved a broad plan Wednesday for capturing more rain. The regulator is launching a road show this month to explain how it will dole out $200 million for projects to collect rain, part of a $7.5-billion water bond voters approved in November 2014.

    The city of Los Angeles expects to collect 3.3 billion more gallons a year from projects now under construction, and eventually plans to capture 20 billion more gallons than the 10 billion it collects during normal years and up to 26 billion gallons during wet years.

    Still, many believe more can be done, through projects large and small.

    "This is a source of water that has been neglected for far too long," said Peter Gleick, president of the Pacific Institute, which authored a 2014 report with the Natural Resources Defense Council that estimated urban California could capture an additional 630,000 acre feet of rain a year, roughly enough for 1.2 million households. "It is untapped, and it has enormous potential."

    Southern California imports a lion's share of its water from Northern California and the Colorado River, on aqueducts that stretch hundreds of miles. The drought has slashed water consumption across the state and renewed interest in developing new water sources, like recycling and seawater desalination.

    California's rainy season usually runs from January to early March with short but intense storms, creating a limited window. Parched Southern California needs the water most, and has long had reservoirs to capture some of it. But much of the water dumped by El Nino's storms streamed down gutters and curbs through a concrete jungle, into drains that go through treatment plants and finally into the Pacific.

    Los Angeles County captured 3.2 billion gallons during this week's storms as of Thursday afternoon, largely through 27 holding ponds, said Steven Frasher, a spokesman for the public works department. Water from the Los Angeles and San Gabriel rivers flowed into fields that percolate into aquifers for future pumping.

    The Orange County Water District, which relies on rain capture for about 10 percent of its supplies to 2.4 million people south of Los Angeles, collected about 3.3 billion gallons from this week's storms as of Thursday afternoon. The captured water flows into the Army Corps of Engineers' Prado Dam and is slowly released 11 miles downstream on the Santa Ana River, to ponds that seep into an aquifer. The rest goes into the ocean.

    "In a dry year we capture essentially all of it. In a big, wet year, we lose more. On average we capture about 50 percent," said Greg Woodside, the agency's executive director of planning and natural resources.

    The San Diego region, unlike Los Angeles and Orange counties, lacks large ground aquifers that can store water. The city of San Diego collected about 800 million gallons this week at nine reservoirs as of Thursday morning, said spokesman Kurt Kidman.

    The San Diego region gets 7 percent of its water from rain on average and about 20 percent during the last El Nino storms in 1998, said Dana Friehauf, water resources manager for the San Diego County Water Authority.

    "There's the potential to do more," Friehauf said. "We have to look at the cost to our ratepayers and see what makes sense."

    Modest efforts are taking hold across Southern California.

    In Los Angeles, the city gutted a 16-foot-wide concrete street median that runs the length of 12 football fields and replaced it with vegetation that captures rain over 111 acres. The $3.4-million project, completed in 2014, is designed to collect enough water to fill more than 27 Olympic-sized swimming pools a year.

    Bloome's group, TreePeople, operates a 216,000-gallon underground cistern at Coldwater Canyon Park, collecting rain from a conference center roof and a parking lot to be pumped for irrigation.

    Even smaller projects are being eyed for potentially big impact. In November, TreePeople unveiled a 1,320-gallon tank at a home in North Hollywood, which can be remotely by computer to drain before major rain, ensuring there is room to capture water. The group plans to equip several more houses by next month.

    "We want to show folks this works for El Nino," Bloome said.

    #2
    World's Biggest Dam Has ‘Extremely Dangerous’ Low Water Levels
    Matthew Hill
    January 8, 2016 — 3:20 AM MST
    Share on FacebookShare on Twitter
    ZIMBABWE-ZAMBIA-DAM-ENERGY-ENVIRONMENT
    The Kariba Dam between Zimbabwe and Zambia. Photographer: Jekesai Njikizana/AFP via Getty Images
    Zambia may have to halt electricity generation at Kariba
    Country depends on hydro power for more than 95% of supplies
    Share on Facebook
    Share on Twitter
    Water levels at Kariba dam, the world’s largest, are at “extremely dangerous” lows that could force a shutdown of its hydro power plants, said Zambian Energy Minister Dora Siliya.
    Poor rainfall and overuse of water by Zambia and Zimbabwe, the southern African countries that share the reservoir, have caused its levels to drop, with electricity generation already reduced by more than half. As of Dec. 28, Kariba was 14 percent full, compared with 51 percent a year earlier, according to the dam’s regulator.
    “The situation is dire,” Siliya told reporters Thursday in Lusaka, Zambia’s capital. “I’m praying. We sit here and gaze at the sky and say, ‘please, the levels of Kariba are at extremely dangerous levels.’” A continued absence of rains could force the power plants to shut down altogether, she said.
    Map: Kariba dam straddles the Zambian, Zimbabwe border
    Map: Kariba dam straddles the Zambian, Zimbabwe border
    Mining companies in Africa’s second-biggest copper producer have had to reduce their electricity use and buy expensive imports at a time when plunging metal prices have triggered the mothballing of some mines and more than 10,000 job cuts. Households and businesses endure power cuts as long as 14 hours a day. The cost of importing power and emergency generation could threaten the government’s 3.8 percent budget deficit target for 2016.
    ‘Most Vulnerable’
    Zambia is the most vulnerable country in sub-Saharan Africa to the El Nino weather system, partly because of its dependence on hydro power for more than 95 percent of generation, Bank of America Merrill Lynch analysts including Oyinkansola Anubi said in a November note. Six of Zambia’s 10 provinces have received below-normal rainfall this wet season, Meteorological Department director Jacob Nkomoki said in comments broadcast on Lusaka-based Radio Phoenix Dec. 4.
    Water flows in the Zambezi river that feeds Kariba on Dec. 28 were 27 percent lower than a year earlier when measured at the Victoria Falls, about 125 kilometers (78 miles) upstream from the dam, according to data from the Zambezi River Authority. At Chavuma, about 600 kilometers north-west and near the river’s source, flows had started to improve and were 23 percent higher on Dec. 28 than a year earlier.

    Water levels at Kariba on the same date were 477.57 meters (1,567 feet) above sea level, barely exceeding the minimum of 475.50 meters for hydro power operations, according to the authority. The government will spend $1.2 billion to mitigate the power crisis, Siliya said.
    The Zambian government has prepared for the possibility of halting generation at Kariba, Siliya said. The measures include setting up emergency thermal power plants due to produce 250 megawatts by early March, as well as a 200-megawatt power-ship to be docked off the coast of neighboring Mozambique, she said. A 300-megawatt coal power station is also expected to start operations by June.
    The country’s power deficit would grow to 1,000 megawatts by the end of December 2015, about half of normal peak demand, Siliya told lawmakers in November. Kariba may have to shut down by October this year if rainfall is low and Zambia and Zimbabwe continue to overuse its water, she said at the time.
    “Our contingency is to make sure that even if we have to shut down there must be power coming,” Siliya said Thursday. “God forbid where we should have a situation where we might say we have to shut them down because the water level is below the minimum recommended.”

    Comment


      #3
      California must have greened up a bit. Good for them, they were getting desperate.

      Comment

      • Reply to this Thread
      • Return to Topic List
      Working...