As cities face increasing populations and long periods of drought, urban areas are being forced to innovate new ways to produce clean water. (Photo: David Berkowitz / Flickr. Slightly modified from original)

Today marks the end of World Water Week in Stockholm, where experts from across the globe convene to discuss the world's water issues. To further explore water stress across the globe, take a look at the interactive maps and resources of Aqueduct, a signature initiative of WRI.

Accompanied by record high temperatures, regions across the globe are currently facing life-threatening periods of drought—the U.N., for example, estimates that a total of 1.2 billion people across the globe live in areas with water scarcity. To ensure reliable access to water, it is essential that cities, home to 54 percent of the world's population, innovate new ways to improve their water supply.

While there's no perfect solution to water scarcity, some cities are seeing success by using new technology and bringing down consumption. Below are three cities gaining traction in the fight against water scarcity:

Los Angeles, California

The City of Angels recently made headlines for releasing 96 million shade balls into the Los Angeles Reservoir. These small black spheres cover the surface of a body of water to slow evaporation, conserving water. The dark coloring and expansive coverage of the balls mitigates evaporation by reflecting the sun's rays back into the atmosphere—providing "shade" for the water.

Like any new program, the shade ball approach has been criticized by some, but it's a bold, concerted effort for a state which recently endured the driest three-year period in its recorded history (2012-2014). Overall, California's conservation efforts have had encouraging results. California mandated a reduction of water use by 25 percent by February 2016, and is on track to exceed that figure, having reduced consumption by 31.3 percent in July.

Singapore

Singapore has long faced a water crisis. The small city-state of five million people relies on four main sources of water: importation, desalination plants, rainwater collection and, most intriguing, the recycling of sewage water (or "recycled water"). Wastewater undergoes a four-step reverse osmosis process which removes all contaminants and toxins, creating clean, potable water.

Despite the safety of recycled water, many refuse to drink it because of the source: waste. However, Singapore is tackling this challenge through strong branding and educational outreach, including a NEWater Visitor Centre.

Qingdao, China

Qingdao, a seaside city in China's Shandong Province, is home to nearly 9 million residents and faces high water demand. To meet its water needs, the city constructed a massive desalination plant with the capacity to produce enough water for 500,000 residents every day. Similar to Singapore's purification methods, the plant uses reverse osmosis to filter ocean water, stripping it of salt and other impurities.

Desalination may appear like a simple way for coastal cities to generate drinking water, but in reality, the process is incredibly expensive, energy-intensive and harms marine life. In spite of this, many water-scarce cities use desalination as a primary source for water out of necessity. Ideally, if a city relies on desalination, the water plants should only be used in case of emergencies and should be powered by renewable energy.

Unfortunately, water scarcity is expected to increase over the coming decades due to growing populations, rising water consumption and climate change. A recent analysis by WRI found that 33 countries are likely to face extremely high water stress by 2040 – just 25 years away. Technology and innovation will be key to addressing this serious issue, and cities across the globe will be vital in implementing safe, sustainable and cost-sensitive solutions.