san francisco city

Two thirsty cities on how they save water now, and for the future

Some cities have to look further than ever before in search of water.  They pump it from further away, look for it underground, take it from the sea, or might tow it from Antarctica. 

However, finding more water is only a part of the solution. “As the saying goes: you can’t build yourself out of a drought,” says Priya Reddy, City of Cape Town’s Director of Communications. If you’ve ever lived through water restrictions, you would know that a key factor of surviving drought is to use the water that is already available, more carefully. We know it here in South Africa, as do many other people across the globe. Squeezing more mileage out of every available drop is recognised internationally as central to managing water efficiently. It is common during drought, but increasingly, this is seen as the status quo in cities of the future. 

As the saying goes, you can’t build yourself out of a drought

Officially, its called Water demand management (WDM), and it was what helped two famous cities recently survive extreme drought. The folks over at Cape Town (Western Cape, South Africa) have been successfully applying WDM for many years, and it helped them drop water use dramatically in a short time, when crisis recently hit. Similarly, San Francisco (California, United States) emerged relatively unscathed from extreme drought without tapping into new water sources.

Both cities are examples of booming urban areas in dry climates that are grappling with water scarcity. Yet, both cities are now stronger in the face of future droughts. Both are now also moving forward towards becoming water wise cities. And, looking at how both did it can be valuable to other cities that are staring a dryer future in the face.

Ways to save water in cities 

Granted, WDM is not easy. It’s actually quite a comprehensive exercise aimed to use the water that you already have, as best as possible. WDM is a long-term approach to managing water, allowing the people in control of the water to manage how residents can use it to some extent. They influence the demand for water, and they try and get everyone to use it efficiently. Almost everybody has to work together to make it happen. Perhaps most importantly, everybody has to think differently about water.

I wrote a handy blog about the details of what WDM in a perfect world entails. But, let’s dig into how our two cities did it…

Welcome to Cape Town  

Cape town recently slashed water use by almost a third in three years, but survived in part due to water demand management (source: Pixabay)

First, a snapshot: renowned Cape Town sits at the southern tip of Africa. The metro area (from Atlantis in the west to Gordon’s Bay in the east) is home to about 4.2 million people. The City of Cape Town has about 610 000 registered residential accounts, and supplies water to businesses, industries and government users.

The city is part of the Western Cape Water Supply System. A system of dams, almost completely dependent on rainfall, supplies water to this system. 

Cape Town Water Supply system

Where the Western Cape Water Supply Systems gets its water from, and where it goes (source: Cape Town Water Outlook 2018)

Saving water in Cape Town

The city started a water conservation programme in the early 2000s already, and has scaled it up considerably over the past few years. “The city has been ahead of the curve in many regards and the pre-existing water demand management programme was an important advantage and foundation for a rapid drought response,” says Reddy. It is why Cape Town could achieve an astounding drop of almost a third in water used – in only three years! This is also what prevented the city from running out of water when a drought like never before hit. Cape Town received the lowest rainfall in the past 30 years. 2017 measured the lowest rainfall since the early 1900s.

How much water Capetonians use 

In February 2015, Capetonians used 1200 million liters per day (MLD) at the peak of summer. This dropped to 1100 MLD under level 2 restrictions by the summer 2015/16. By summer of 2016/17, the water used peaked at 900 MLD  (under level 3 restrictions). This stabilized at 600 MLD between June and December 2017. Since January 2018, even less water have been used –  closer to 500 MLD. 

This number is a saving of 68% at the peak of summer, and a saving of 45% on average over the year.

Cape Town fine tunes the system

Water restrictions contributed immensely to dropping the amount of water used in Cape Town, but it was not the only one. Some of the most important results were due to the city fine-tuning the system that the water is piped through. In particular, advanced pressure management has had the biggest impact. This contributing an average saving of 55 MLD, says Reddy.

“Advanced pressure management” is when they drop the pressure in the pipes so much, less water comes out of your tap. City management knows where the people are that still gobble up too much water. Once those liters start disappearing, the city can “throttle” the supply “to the extent of partial supply.” Already started more than a decade ago, pressure reduction has been accelerated and expanded. At the hart of this programme is automated pressure zones, allowing the city to zap the pressure up or down remotely. 

Cape Town is also the South African city that looses the least water. They are logging the lowest overall losses of any South Africa metro at 16% – the national average is a whopping  36%. Reddy says this is thanks to proactive management of resources and the application of innovative technology. Simple actions include fixing leaks at households. But, an advanced robotic crawler also patrols the pipes. Fitted with an on-board camera and remotely controlled, the crawler monitors water and sanitation pipelines, identifying cracks, leaks and obstructions. 

Household flow regulators are already employed, but will be ramped up in future. These will restrict high water users, and can stop water loss when there are leaks in the pipes. Small things like warning letters included in the municipal bills of high-water users impacts motivates for better behaviour.

Furthermore, the city is also continuously clearing alien vegetation in the catchments and on city land.

Working with the customer 

Awareness campaigns are nothing new in Cape Town. In fact, they describe it as ongoing, successful and sustained. The campaigns are part of the city’s multi-faceted, multi-platform water communication approach. The aim of all of this is to drive demand down. They also aim to keep consumption at appropriate levels as the situation requires, says Priya. The approach includes extensive messaging and education, over a wide range of media and interventions. It is part of a dedicated stakeholder engagement philosophy. Part of the core is the city’s website. “All city water-saving or drought collateral was and continues to be made available in open format to anyone who requests it.”

Highlights on the site include the green dot map. This interactive map shows water users in which category their water usage falls. The number of dark green dots (households using less than 6 kl/m) have increased from 150 000 to 219 999 from December 2017 to March 2018. “This is intended as a positive behavioural enforcement tool with analytical capabilities,” says Priya. 

It also takes money…

In February 2016, the city introduced level 6 water and sanitation tariffs to try and influence behaviour more. The tariffs were also part of an attempt to make back some of the revenue to city lost because people had less water to use and thus, pay for.

This is a common, though often unplanned for, affect of drought. Similar tariff hikes were applied in São Paulo after their water crisis in 2015. Looking back, one of the lessons they shared is that planning for drought must include financial planning.  

At the end of May this year (2018), new level 6 tariffs was approved for Cape Town, with level 7 disaster scenario tariffs in place. “The idea is that we could move between these tariffs as the situation requires,” says Priya. 

Cape Town has managed to drop the amount of water used in the city by unbelievable amounts. Still, it needs to drop even more. The National Department of Water and Sanitation allocated the city 450 million liters to stretch the available water throughout the year.  This means each person has 50 litres per person per day. According to Reddy, “based on what we have achieved thus far, we can do it.”

Welcome to San Francisco 

San Francisco, water demand managment experts

World renowned San Francisco is also famous for their super efficient management of water (source: Pixabay, Adam Derewecki)

First, let’s take a quick look at San Fran, northern California. A few quick facts: the hilly city hugs the Pacific Ocean. It’s home to the Golden Gate Bridge! It’s often in the news because of wildfires and drought. 

Water here is managed by the San Francisco Public Utilities Commission (SFPUC). They serve over 2.7 million people in San Francisco and throughout the San Francisco Bay Area. People here use most of their water indoors. Only families with their own yards really use water outside. Most people here live in building shared with other families (like complexes and flats). If if they have yards, well under 50% of the home’s water is used outside – its’s more like 10%.   

San Francisco residential water use
This is how people in San Francisco use their water (supplied by the SFPUC)

The SFPUC owns and operates the Hetch Hetchy Regional Water System (RWS). High-quality drinking water from the Tuolumne River watershed (85%) in the Sierra Nevada and protected local watersheds in the East Bay and Peninsula (15%), flow into the RWS. The Hetch Hetchy Reservoir in Yosemite National Park collects water from the Tuolumne. Water then flows down an aqueduct system for almost 270 kms (167 miles) to the bay area reservoirs and customers. In 2018, the SFPUC started adding groundwater to the mix. Hetch Hetchy regional water system

Saving water in San Fran

The folks over at San Francisco have been running a comprehensive water conservation program for over 25 years. They are experts, and use almost the entire range of WDM strategies. “Demand management continues to be an important component of our water supply management approach,” says Steven R. Ritchie, SFPUC Assistant General Manager, Water.

As I’ve mentioned, the state of California is no stranger to drought. Yet the most recent (2012 – 2016) broke records. The governor declared a drought state of emergency for California in January 2014, and lifted in April 2017. The period included both the region’s driest and warmest year on record (2014). The next year, 2015, was the second driest and hottest (2015). One major consequence was an astounding death of trees. An estimated 102 million trees died from 2010 to 2016. In 2016 alone, 62 million trees died. The dead trees created a dangerous amounts of fuel for wildfires.

How much water San Franciscans use

Before this drought, Steven says that demand for water was already lower than the estimated 1205 MLD (265 million gallons per day (MGD)) that they plan for, due to the 2008-2009 financial crisis. In 2013, demand was at around 1018 MLD (224 MGD). They have triggers built into their storage system to declare rationing. Before this could happen, the government announced a drought state of emergency. At the height of the drought, they still delivered 822 MLD (181 MGD). This equals about three years of water supply left in storage.

San Francisco residential area

A residential area in San Francisco city (source: Pixabay)

In 2013, (pre-drought) in-city residential water use per person per day was approximately 185 liters (49 gallons). In 2017 (during drought), this dropped to 155 liters (41 gallons). After the drought, in 2018, the figure rose again slightly, reaching around 162 liters (43 gallons). “This is still one of lowest in the State and almost half the statewide average,” says Steven.  

How San Fran fine-tunes the system

For this city, some of the biggest results were from replacing old household items. Over the past 20 years, the replacement of old, high-volume toilets and washing machines have played a major role in reducing indoor water use. “Nationwide, the amount of water used for toilets and clothes washers in a typical home has shrunk from about 50% in the 1990s to about 40% today in houses that have new fixtures,” says Steven.   

Other elements of success that they list are: 

  • Plumbing codes that require efficient fixtures such as toilets, aerators and shower heads;
  • A process to determine which interventions are the best, taking cost, effectiveness and practicalities in mind;
  • A water conservation plan that a timeline for activities and has the necessary resources and budget available. Success must be measurable, and it must allow changes accordingly. 
  • They understand their customers, what they need, and which conservation measures would best meet these needs.

Working with the customer 

The SFPUC reached out to San Franciscans about the need to save water in many ways. Campaigns included resources to help. They ran presentations at neighborhood groups and visited businesses in person. At the same time, statewide media covered the extensive drought.  

In June 2014, they launched a multilingual “Water Conservation is Smart and Sexy” education campaign. The campaign included everyday water conservation tips and information about the drought. This continued throughout the drought, and was ran on a combination of television, newspaper, billboard, bus, commuter transit station, and social media channels. The campaign encouraged people to use water more wisely, and to use water-efficient plumbing fixtures. 

Smat and sexy water conservation campaign
The Smart and Sexy campaign in action (image supplied by the SFPUC)

They also referred people to their website to learn more about conservation services that are offered. Shortly after launching the campaign, the water conservation web traffic increased by close to 25%. 

Steven says their outreach efforts were very effective in motivating residents to use less water.     

Keeping the strategies that worked   

Water managers at both Cape Town and San Francisco says the future entails repeating much of the same, while moving forward towards building ever more resilient cities.

The people at Cape Town say all their efforts to date were successful overall, and they would repeat it if they had to start over. However, they might re-look the timing or scale of some approaches. For example, how to introduce or communicate initiatives, how to make initiatives more effective and what capacity they need ti implement their plans.     

Come rain or shine”, the focus of the San Francisco conservation program will continue to be helping customers use water wisely. They will help people avoid leaks, replace old or broken equipment, and stop inefficient water use. 

For both cities, a strategy to save water into the future has many elements. Priya says they will always apply a combination of factors. They have learned that different reasons motivate people to change.  Some people feel a sense of social responsibility. Money is the motivating factor for other people. 

At San Francisco, once drought hits, they will again run extensive outreach and media campaigns. They could combine this with fees, monitoring the water use at homes, and run incentive programmes to save water.    

Lead a team by example 

Both cities also see any future plans as a team effort. Driving awareness is a sustained, long-term effort to change behavior. It is critical that a range of partners who share the same key messages support the City of Cape Town, says Priya

At the same time, the custodian of water supply, such as the City of Cape Town, must lead by example, maintain infrastructure, be innovative and consider water in all operations across the city.

The custodian of water supply must lead by example

Steven adds to this, when listing accountability as a critical element of any water-saving incentive program in San Francisco. For them, this means no longer offering clients rebates and incentives for water saving fixtures, devices and equipment without their staff inspecting these to ensure they function correctly. 

Two cities plan for the future

At both cities, they are planning long term to secure water into the future. Plans for both include new water infrastructure, sourcing water from new sources and transferring water from other places. Plans will also focus on conserving water, and recycling water.    

Both cities are also embracing new tools and approaches to managing their water. Cape Town is refocusing its approach towards the more comprehensive concept of “a water-sensitive city”.

Here is how people over in Australia see a water sensitive city: 

The SFPUC has adopted an OneWaterSF approach. Their vision is as follows: With our OneWaterSF approach, San Francisco will optimize the use of our finite water and energy resources to balance community and ecosystem needs, creating a more resilient and reliable future.

Steven says “The SFPUC has successfully cultivated a shift at the utility from thinking about one project at a time to thinking holistically about the synergies and resource potential across water, wastewater, and energy boundaries, exemplified in the promotion of on-site non-potable water systems that collect, treat, and use alternate water sources for non-potable uses within individual buildings or across multiple properties.”

Global thinking

Both cities’ plans are in-line with global thinking of how cities should function for a sustainable future. According to manager for the International Water Association (IWA) Cities of the Future programme, Corinne Trommsdorff, the application of successful WDM is multi-faceted. Water-wise citizens, decision makers, and professionals should be shaped.

The way that buildings and neighbourhoods are designed should be reassessed

Action should also take place at basin level; assessing constraints and the means to minimise risk to water shortage. The way that buildings and neighbourhoods are designed should be reassessed, allowing for minimal consumption while maintaining high livability. The implementation of improvements or modifications to water services – water loss reduction, reuse for different purposes and rain water harvesting – are essential.

“WDM is not just about technology, but about people working together towards a shared objective.”

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