Vizag's dirty secret

Vizag’s dirty secret

Nallah nostalgia

Storm water drains form naturally over time when rain water runs-off the land towards slopes. We also call them “nallahs” or “geddas”. Vizag has hillocks on three sides and a sea on one side. It is natural that all the rain water to gush quite quickly down the slopes and into the sea. Along the way the storm water gathered in some of the low lying areas forming natural reservoirs before making its way to the sea. Vizag always had an excellent natural storm water drainage system. A survey of India map of Vizag in 1929 shows that we had 31 km of storm water drains within the smaller Vizag at that time and 300 acres of water bodies that these storm water drains drained into.

Fascinating ecosystem

This system of natural storm water drains was an ecological wonderland. Tall grass grew all along the nallahs and played host to myriad creatures. At the bottom of the food chain were the worms, grasshoppers, mantis, tadpoles, frogs, snails and crabs. These creatures attracted a variety of aquatic birds.  Lapwings, sandpipers and kingfishers filled the underbrush. Raptors such as Marsh harriers and Bonelli’s eagles hovered above the reed beds, diving spectacularly to pick up an occasional live snack. During the rainy season when the streams and ponds were full, little fish would dart through the water and children would spread a cloth trying to catch them. Along with our rivers, these nallahs carried land based nutrients and sand to our beaches, enriching our near coast waters and nourishing our beaches.

How our nallahs died

Wise cities around the world would have used the natural drains as beautiful assets but our city planners did not realize the potential of these valuable nallahs. Buildings came up alongside these nallahs and instead of using them as attractive “water fronts” they were used as dirty backyards. Builders encroached on to these nallahs and they soon became too narrow to carry adequate volumes of water. Migrant workers arrived in the city for work and occupied these government lands. Slums sprang up and the residents used the nallah as open air toilets. At the same time consumerism grew and the age of plastics was upon us. Soon everyone began to throw anything and everything into the nallahs. Stagnant waters encouraged mosquito breeding and malaria became rampant. Our once beautiful nallahs became stinking dangerous drains. RIP our nallahs.

 

Vizag’s dirty secret

Nowadays these nallahs pass silently and secretly behind our homes, leaving a foul stink in their wake, carrying the evil filth of our city to the beaches like a black, slow moving liquid conveyer belt. No one wants to talk about them. When it rains, these drains already clogged with plastics, Styrofoam, building debris and other assorted material overflows on to the roads. During Hudhud every gedda in our city and more so near our port vomited up tons of plastic making our roads look like rivers of plastic and rubbish. Except the “uplands” area, every other part of Vizag is prone to flooding because of nallah overflow.

Big network - big issue

Vizag’s storm water drains network is no small thing. There are in all 22 major Nallahs and 20 primary drains passing through the GVMC territory. The length of the primary drains is around 110 Km. (City Development Plan, Ministry of Urban Development, Government of India). Several recent studies have been commissioned and reports have been submitted as to how to tackle the problem. While VUDA is responsible for the city planning, the storm water and drainage system is GVMC’s responsibility. Going by the documentation available on the net the corporation is seized of the issues and has plans to tackle the problem. But are they on the right track?

Natural is best

While some engineers feel that lining the nallahs with concrete would overcome silting problem and accelerate the flow of storm water, the problem is that it stops water from seeping into the ground and improving the city’s water table. Some nallahs have vertical side walls ostensibly to define the nallah border and curb encroachment. During rains the nallahs needs plenty of space to carry the increased volume of water. Vertical walls reduce the cross section of the flow area and speeds up the flow. So when the water hits a bottleneck in the nallah system it’s like a truck hitting a wall. The water has no place to go and floods the surrounding area. Ideally the nallahs must have enough natural banks to accommodate increase of water flow but this is not possible in some crowded parts of the city. Where the nallahs pass through crowded commercial areas or under culverts, the corporation has put up a high wire fence to prevent folks from chucking rubbish into the nallah.  Until we mature as a civic minded society – say in about a thousand years - this probably is the only foolproof solution. However considering the seriousness of the problem we should be putting up surveillance cameras and penalize the offenders out of this pernicious habit.

Dealing with the present

There are limited options to handle the existing nallah problem, we must 1) limit plastics use with strong laws 2) remove building encroachments that narrow the nallahs, these offending properties are generally owned by the rich and famous 3) relocate nallah-side slums in a phased manner 4) entrust sanitary inspectors to identify houses that discharge sewerage into the nallahs and stop the practice 5) increase de-silting operations 6) install mesh barriers in easy to access points of the nallah and clear nallahs at these points frequently 7) ask the port and railways to clean up their nallahs 8) encourage citizen whistle blowers to report nallah misuse and encroachments. These steps will greatly mitigate the current problems.

Dealing with the future - treat nallahs as assets

As the city expands, city planners must plan differently for the new areas. For example they must 1) contour the nallahs with gently sloping banks - this is good for birds and humans and a buffer for sudden surge in run-offs 2) plant the slopes extensively, put in a few benches and swings – VUDA’s open-to-built area ratio will benefit greatly 3) lay a 2m wide walking/cycling track alongside the grassy slope, citizens will be able to cut across the city without suffering the traffic 4) lay a 7m wide road on either sides of the major nallahs, then a pavement and then allow building developments.  Buildings alongside these streets will become premium waterfront properties and bring in substantial tax revenue. The old bad planning is still being practiced in the new expanding Vizag. VUDA must get its act together quickly before the future nallahs become like our present ones. If we do it right, Vizag’s nallahs could change from dirty secrets to shining examples.

This article appeared in the Times of India on 17th May 2015