Wednesday, March 21, 2012

Case Study: Water Infrastructure in Karachi, Pakistan

Karachi's Drainage Systems Map
(Click to Enlarge)
Karachi, Pakistan suffers from many problems: economic, social, infrastructural.  In anticipation of exponential population growth in the coming years, that Asian Development Bank funded the Karachi Mega Cities Preparation Project.  The project seeks to identify the structural problems hindering economic growth of the city.  This case study will explore reoccurring infrastructural problems highlighted by the Asian Development Bank that pertain to water and sanitation systems.

Water Service
The Karachi Water & Sanitation Board (KWSB) is a government agency that receives funding to provide water services to Karachi.  Due to its close proximity to the coast, Karachi’s groundwater is mostly saline and not potable.  Therefore, the city draws its water mainly from two surface water sources: the Indus River and the Hub Dam.  The Indus River is over 100 km away from the city’s center, while the Hub Dam is only 35 km away.  KWSB pumps a total of 540 million gallons of water per day to the city.  Of this, only 350 million gallons of water is treated daily at the Hub Dam.  Treatment consists of clarification, filtration and chlorination.  The remaining 190 million gallons of untreated water flow directly from the Indus River to pipelines connected to domestic residences.  Not surprisingly, untreated water is not differentiated for industrial or commercial use.  An existing project (in the works as of 2005 when officials drafted the original Karachi Mega Cities Preparation Project) plans to expand the Indus River’s extraction capabilities by an additional 100 million gallons per day.  Once completed, the shortfall of treatment capacity will have astoundingly reached close to 300 million gallons of untreated drinking water pumped to the city each day. 

In large parts of the city, water access is only intermittent.  KWSB provides neighborhoods with water on a “rotating basis,” which, according to their optimistic claims, means supplying water to all areas for at least 2-6 hours each day.  The Karachi Mega Cities Preparation Project report suggests KWSB’s estimates are over-exaggerated; services often operate only 2-3 times a week.

The unreliability of the network stems from the combination of variable water pressure and “unaccounted-for-water” leakage.  The lack of constant pumping to all pipes connected to the water grid and the existence of poorly attached “informal” connections interrupt the water flows and effect water pressure.  The Asian Development Bank concludes that “intermittent flow and variable pressure in the system [] allows the ingress into the supply system of faecal contaminated groundwater and surface water.”  Tellingly, the World Health Organization found that over 75 percent of water samples coming from Karachi are substandard. 

Even with overextended pumping, only three out of every four households have piped water connections.  The rest of the population receives their drinking water from tanker trucks[1] (14 percent), groundwater wells (1 percent), and other protected sources (8 percent).  Piped water connections in Karachi are often illegally connected.  For example, in the Katchi Abadis neighborhood, 30 percent of the residences have “informal” connections.  The Asian Development Bank goes even further, estimating that 50 percent of pumped water is “unaccounted for” within the network.  That means that with projected delivery of 635 million gallons of water a day, 320 million gallons are unaccounted for.  Unfortunately, KWSB has trouble identifying where losses occur due to an absence of domestic metering.

Only 1 percent of KWSB customers have water meters that track usage.  They account for 65 percent of KWSB’s total revenue collection, but only 17-20 percent of water volume consumed.  Of the customers that do have meters, only 28 percent have functioning ones.  KWSB therefore estimates charges for customers with broken meters based on past usage billing rates.  

Other water customers are billed based on the size of the land plot or apartment area.  On average, residents spend 5 to 8 percent of their monthly income to purchase water.  As part of the government mandates for KWSB, price levels have remained constant over a ten year period, even as expenses have risen 40%.

Sewage and Wastewater
Most households in Karachi have either sewage or septic tank connections.  89 percent of households have a flush toilet.  Karachi residents produce an estimated 370 million gallons of blackwater a day (in 2006).  For those connected to the sewage system, there are three wastewater treatment plants.  But the three plants combined only filter 151 million gallons of water a day – 40 percent of the total sewage produced.  The Asian Development Bank attributes the poor productivity of the wastewater treatment system to “inadequate maintenance and frequent blockages caused by solid waste entering the plants.” 

Sewage collection pipes operate overcapacity, which leads to the frequent blockages.  Like with the potable water distribution system, the sewage system does not operate at its fullest efficiency.  Karachi sewage pipes, made of cement, often clog and crack.  The pipes then remain broken as a result of poor maintenance and monitoring.  Sewage pipe leakages cause “ponding of stagnant and focally contaminated wastewater and presenting a danger from water-borne (through ingress to water supply lines) and other water related (insect-borne and water-washed) diseases.”

Combined with dumping, only around 25 percent of sewage flow actually reaches one of the treatment plants.  Karachi pours the rest of its wastewater into the stormwater drainage networks.  For example, industrial dumping accounts for 92 million gallons of contaminated wastewater per day entering the stormwater drainage system.

Stormwater Drainage

Although Karachi experiences little precipitation throughout the year, during monsoon season the city floods.  Lack of master planning and blatant disregard for controls (when they do exist) lead to indiscriminant building.  Development therefore occurs on top of natural drainage channels, which cause additional flooding during heavy rainfall.  

The stormwater drainage system consists of drains and nullahsNullahs are concrete-lined, open-aired streams intended to redirect stormwater.  They are designed to collect flood overflows generated during the monsoon season.  In Karachi, 41 main drains and 167 km of nullahs make up the stormwater drainage system.  There are also informal drainage systems of up to an estimated 1,000 km, although individually these are small in scale.  Unfortunately, systematic wastewater dumping contaminates the nullahs’ open flowing stormwater.

The nullahs feed into three sites: the Malir River, the Layari River, and the Karachi harbor (thus eventually drifting to the Arabian Sea).  Nullahs release untreated stormwater (and raw sewage) directly into these waterways.  Ultimately, the city dumps 200 million gallons of untreated wastewater and up to 1,000 tons of solid waste into the Karachi Harbor every day.

The Karachi Mega Cities Preparation Project report summarizes, “Both surface water and groundwater sources are increasingly polluted due largely to the disposal of untreated domestic and industrial wastewaters to rivers, nullahs and irrigation systems.  There is inadequate sewage treatment capacity, and where it does exist, it frequently operates ineffectively.”

Water Distribution
The Karachi Water & Sanitation Board does not adequately administer its services.  First, the city fails to monitor potable water outflow.  Without meters, KWSB cannot effectively charge for water usage, and, more importantly to the structural sustainability of the system as a whole, cannot track abnormal usage patterns.  This inability to detect “leakages” has persisted so long that the entire water distribution system cannot economically provide for Karachi’s citizens.  With the addition of the extra pumping from the Indus River, KWSB will pump 640 million gallons per day into the city.  Of that, only 350 million gallons will be treated daily.

The Asian Development Bank supports a twofold plan for tackling water distribution problems.  The water supply system has become a financial burden that does not pay for itself and thus discourages further investment.  The Bank proposes that KWSB expand its metering capabilities so as to increase tariffs and revenue collection.  As a secondary benefit, metering will invaluably increase distribution efficiency by allowing KWSB to track where use fluctuations occur.  KWSB can then respond quickly to problems.  

To reduce costs, meters do not need to be located at the individual building level.  KWSB could install meters at the street level or neighborhood level so as to recuperate costs lost from illegal connections and to encourage local self-policing.  Usage based billing, as opposed to the status quo land area based billing, will also encourage more restrained usage that will put less stress on the overworked distribution system.  Separate government subsidies need to go to those who cannot afford water, but even so, their usages must be tracked. 

Additionally, the Asian Development Bank will also authorize a study to define specific strategies to reduce unaccounted-for-water leakage.  Their goal is to recuperate costs on 100 million gallons more water per day than the KWSB currently does.  Although it moves in the right direction, the plan will still leave 240 million gallons of untreated water pumped daily into distribution pipes.  Any plan to address Karachi’s water distribution problems must increase the capacity of the water treatment plan.  Cost constraints may limit ambitions, but plans need to consider the immeasurable benefits that accompany potable water treatment (ie health and productivity externalities).  If left untreated, which is likely the case, Karachi needs an educational campaigned designed to increase awareness of waterborne diseases and how to filter, boil, or treat water at the household level.  The Asian Development Bank does not mention any plan to promote public knowledge regarding clean drinking water.

Wastewater and Stormwater
Karachi clearly does not represent a closed water system.  Originally, water supply is taken from over 100 km away in the case of the Indus River.  KWSB transports this water to the city for consumption, and then effectively pours wastewater directly into open streams, rivers, and the ocean.  This is by no means sustainable.  Treatment plants operate over capacity.  Open dumping creates rivers (literally rivers!) of waste/stormwater hybrids.  These have detrimental environmental, aesthetic, and public health effects.  

In response, the Asian Development Bank correctly commissioned two major courses of action for waste and stormwater treatment.  The Bank will sponsor a study on strategies to decrease the practice of sewage dumping.  Strategies will explore physical and financial responses as well as the implementation of public awareness campaigns.  To increase resilience and grow closer to a closed water system, the study will also investigate the possibility of irrigating crops with treated wastewater.  

Additionally, the Bank will fund the drafting of a drainage system master plan.  This will include provisions on how to separate wastewater from stormwater.  Important in stimulating discussion on the topic, the master plan will also map natural, manmade, and proposed directions for these two flows to follow.  This map will serve as the foundation to track, monitor, and plan for future developments in water, wastewater, and stormwater infrastructure.

Closing Comments
For the 4 water and sanitation related projects the Asian Development Bank will commit $1.26 million – $710,000 for water distribution and $550,000 for sewage and stormwater disposal.  While the Karachi Mega Cities Preparation Project establishes guidelines to formalize the city’s infrastructure, the city will still have to cope with rapid population growth.  With a 4.5 percent annual growth rate, Karachi will explode from a city of 16.4 million in 2007 to 26.4 million in 2020.  Existing water systems infrastructure already operates over capacity and the Karachi Mega Cities Preparation Project fails to address future growth strains on the system.  The Asian Development Bank begins to lay the premises for further development of water infrastructure.  However, with the growing influx of poor rural migrants likely to stress water networks and continue trends of informal water connections and illegal dumping, can Karachi truly expand its water and sewage collection, treatment, transportation, and disposal capabilities?  The Karachi Mega Cities Preparation Project may look at the symptoms of Karachi’s water problems, but it unfortunately ignores the root causes.

[1] Tankers often supply water for inflated prices between $4.50 a gallon and up to $16 per gallon (often managed by Pakistan Rangers who take the water directly from hydrants at no cost).