Saving lakes in Chennai: Maps, markers important


Encroachment of the Velachery Lake in Chennai
The Velachery Lake in Chennai. Residents right here say that at the least a 3rd of thelake, because it was within the 70s, has made manner for retailers and homes. Pic:McKay Savage/Flickr (CC BY:SA 2.0)

Chennai’s checkered historical past of water administration has come beneath the highlight each time the town has discovered itself nose to nose with a disaster, such because the catastrophic floods of 2015 or the unprecedented drought confronted by the town in 2019. Consultants have repeatedly referred to as for higher administration of water sources, alluding to the truth that the town’s many water our bodies might be the reply to its water woes, if they’re managed higher. There have, in actual fact, been some concerted efforts lately to revive and handle the tanks and lakes in Chennai.

Nevertheless, there are a number of organisations and departments concerned, which provides to the problem of safety and restoration. Massive water our bodies within the metropolis are beneath the management of the Public Works Division, consuming water sources beneath Metro Water, temple tanks beneath the Hindu Non secular and Charitable Endowments (HR & CE) Division whereas the smaller lakes are managed by the Chennai Company.

Of those, the lakes beneath the Chennai Company have been the main target of its restoration efforts with greater than 180 our bodies, giant and small, having been restored up to now three years with 20 extra within the pipeline. Whereas there is no such thing as a checklist within the public area for odd residents to seek out out which the restored lakes are, or that are a part of the bigger plan, the Company places out updates by way of their social media channels, as and when a selected restoration undertaking is full.

Learn extra: Round 100 water our bodies in Chennai set to get a brand new lease of life; right here’s how

However whilst some steps have been taken to handle the water our bodies, there have additionally been frequent complaints towards encroachment and the ensuing loss or shrinkage of water our bodies. Allegations of encroachment mechanically elevate the query of comparability with authentic lake beds and unfold. How does one know concerning the authentic unfold of the lakes in Chennai? What are the instruments used to map them or calculate the extent of encroachment?

Public reminiscence

Take, for instance, the sluggish shrinking of the Velachery Lake. It has been a topic of repeated debate with little motion. Chennai misplaced 2389 acres of water our bodies between 1979 and 2016, with Velachery lake being one among many such shrunken lakes in Chennai. Public reminiscence has been a manner of documenting the modifications to the lake. The emergence of many homes and business institutions over what was as soon as waterbed is frequent information.

V Somasundaran, a retired BSNL worker, says, “I’ve lived right here all my life. We purchased land right here within the 70s. Again then, while you went as much as the terrace of my home you would see the sprawling lake. As increasingly plots have been offered, we may visibly see the dimensions of the lake scale back over time. From the place we as soon as loved the sight of this large lake, I can now see that at the least a 3rd of it has made manner for retailers and residences. Then folks marvel why the world floods when it rains!”

Related tales could be heard throughout the town from very long time residents who recall sighting of migratory birds and having fun with the cool breeze from the lakes. As we speak, they discover most of it constructed upon, their tales the one testimony to what has been misplaced. 

When members of Arappor Iyakkam, an NGO, got here throughout a reclassification notification on the web site of the Chennai Metropolitan Improvement Authority, they realised that the survey quantity matched that of the Pallavaram lake. They despatched an objection letter towards reclassifying the water physique to a residential zone. Such permissions to reclassify water our bodies is how lakes are encroached in small parcel. The lake in query right here has already shrunk from 120 acres to round 50 acres.

Land use reclassification notice on CMDA website
Particulars of reclassification discover on CMDA web site. Pic: Arappor Iyakkam

Those that struggle lake encroachment use public sentiment to drive their trigger to a big extent. “The recollections are an essential a part of what motivates them to struggle to avoid wasting the water our bodies. We entry land information to make our case, however typically even these aren’t correct and can’t assist us gauge the true space of the lake mattress initially. In that case now we have to fall again on public testimony,” says Vivek M, a resident who has been elevating consciousness on lake encroachment in Villivakkam.

Learn extra: The sluggish killing of Korattur Lake: Can or not it’s reversed?

The most important difficulty in lake conservation is figuring out who owns the lakes in Chennai. Some our bodies are managed by the Company and others by the PWD. Residents have to achieve out to officers to know who controls a selected water physique. “Throughout restoration efforts, native residents have typically discovered that some water our bodies and ponds didn’t seem on the Company’s checklist of water our bodies beneath its management. In such circumstances we examine the income information after which a surveyor from the collectorate comes alongside to find out the boundaries earlier than the restoration efforts are undertaken. A majority of such water our bodies are positioned within the expanded areas that have been added to the Chennai Company in 2011,” says a former member of an NGO within the metropolis that was concerned in lake restoration.

The place is the documentation on the lakes of the previous?

Land survey information from the previous are one of many key sources that may assist gauge the preliminary areas and unfold of the lakes in Chennai. These information are maintained by the income division. However with current developments in expertise, GIS mapping provides a few of the greatest means to evaluate the true space and site of lakes and monitor any modifications actual time. Digitization of the lakes, nevertheless, has been occurring at a sluggish tempo.

In a current ruling, the Madras Excessive Courtroom has ordered that the income authorities should full digital mapping of the lakes in Chennai and make these recordsdata obtainable to most of the people on their respective web sites.

What’s GIS?

GIS is geographic data system used to create, handle, map and analyse varied types of information. GIS is used to mix spatial and non-spatial information and helps authorities in planning and decision-making.

“Up to now, now we have solely been counting on the income information to identify or quantify the encroachments within the lakes. GIS mapping is nevertheless a course of that may take a while to finish precisely, it’s not one thing that may be carried out in a couple of weeks’ time. As soon as it’s performed, it is going to additionally make our work simpler,” says an official from the income division. 

Empowering residents with information

Whereas some residents are conscious of the existence of lakes or encroachments, many have no idea if a brand new plot they’ve purchased or an condominium they’ve bought is definitely on land that was as soon as a lake. “I didn’t know this was previously a lake mattress after I purchased a flat right here. However the flooding in 2015 was intense. We have been marooned for a couple of days and solely after I learn information reviews did I realise that this piece of land was as soon as part of the tank,” says Guru P of Perumbakkam.

However how can residents actually discover out? Referring to the occasion of Pallavaram Lake talked about above, David Manohar, an activist with Arappor Iyakkam, says, “To forestall such cases of encroachment, not solely do we want satellite tv for pc mapping, which the authorities have been sluggish to undertake, we additionally want bodily markers denoting the boundaries of water our bodies. That’s how each frequent man will know the extent of water our bodies. The markings ought to even embrace encroachments, in order that future consumers of the land are dissuaded from buying it. It’s not simply the lakes however the varied channels that join them which might be topic to such encroachment. In the end, such acts are the basis reason behind flooding.”

On how data accessed by the NGO might be obtainable to the frequent man, David says that the method is labyrinthine. Once they come throughout any occasion of encroachment, the group obtains the maps from the income division utilizing the survey numbers and compares them towards the bottom scenario. In different circumstances they’ve needed to file RTIs to acquire such data. It’s a course of that includes chasing blind leads and figuring out the place to look. This drawback might be remedy by easy marking of boundaries over not simply lakes however all commons. Proper now, in David’s phrases, it’s all “a thriller”.

Pallavaram Periya Eri
The northern aspect of Pallavaram Periya Eri. Pic: Renu Karthick Sugumar

How possible is lake mapping?

For GIS mapping, capability constructing is a key requirement. Raj Bhagatt, Senior Supervisor of WRI India, says “We’ve got information for all sources however the digitisation of such information rests solely on the initiative taken by the native authorities. A structured effort to digitise information will contain coordination from a number of departments. Whereas not not possible, it is going to require a correct plan from collation to software. Proper now it’s exhausting to entry even fundamental data akin to district boundaries or city/village/ward boundaries.”

For residents to profit from the provision of such data, Raj says that the one manner ahead can be to open supply the info. Open information will permit entry to those that search to be taught extra concerning the sources and assist in their trigger for conservation. He speaks of the efforts of GIS mapping performed in Karnataka that might function a blueprint for Tamil Nadu if the state chooses to undertake giant scale digitisation. Spatial information there’s obtainable to all, not simply the officers and choose few people. 

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