From Dr S. Subramanya <email@example.com>
Here is a section of Justice Patil Committee recommendations on Lake Restoration that all lake restoration programmes/DPRs should comply with. This is something that all Resident Lake Committees/Societies should be aware of.
Ecological Perspective of lake restoration:
The purpose of any lake restoration programme is to keep the area of the lake intact by removing encroachments, provide for impounding only clean water and safeguard the ecology of the lake. Some of the ecologically sound techniques for lack restoration are listed hereunder and Detailed Project Reports have to be prepared keeping these principles in view.
a) On Island Design: Islands in lakes are used by birds and other biota for resting, roosting and nesting. For this, islands need to be well away from human activity and should be located at sufficient distance from the main-bund and water-edge in such a manner that the surrounding water provides sufficient insulation from ground predators and human activity. Unless the area of the lake is more than 20 Ha, it may not be wise to plan for island formation in the lake under restoration. Reed planting on the islands must be based on careful selection and based on a clear understanding of bird use of islands. The design of islands and choice of trees for plantation is given in Annexure-XIII.
b) Walkways above High Water Mark instead of Jogging Tracks: Instead of ringed elevated jogging tracks, a packed-mud/ cobble-stone ground-level walkway can be developed with a width not exceeding 3 mt (three meters). This can be established all around the lake perimeter beyond the high-water mark or close to the perimeter fence. Such ground-level walkways will not obstruct the inflow of run-off water from the surrounding catchment area, wherever it is still exists.
c) Planting of tank area with trees and bushes above high water mark: In the open lake area that spreads above the high-water mark and the perimeter fence, select trees and bushes that are beneficial to birds, butterflies and other biota can be planted. List of such trees is listed in Annexure-XIII.
d) Designation of lakes as bird sanctuaries (with no boating and commercial fishing): Historically, the lakes in Karnataka have supported immense aquatic biodiversity including birds and other biota. Lakes that have a past history of supporting high bird diversity in terms of species richness and their numbers should be identified in consultation with competent personnel/birdwatchers and declared as bird sanctuaries. An in situ development and management plan should be drawn-up by treating each lake as a unique case. Such lakes should be identified as unique bird habitats/bird refuges, should be kept free of all disturbances like boating and other water-sports, commercial fishing, poaching, etc, and notified for protection as per the Wetland Rules, 2010.
e) Management of Raja Kaluves: No encroachment, sewage inflow or garbage dumping must be allowed into Raja Kaluves. In addition, appropriate silt and waste trapping structures may be set up at regular distances of the Raja Kaluve. Protection of these canals are critical as they lifelines for the survival of lakes and harbour immense potential for biodiversity conservation, recreation, and grazing and farming, including urban community gardens. With imagination and innovation, Raja Kaluves can easily become the space for building ecologically committed communities in urban areas. The Raja Kaluves that are not encroached, or partially destroyed, must be protected from further encroachment and destruction by live fencing as though they were tree wedges interlinking lakes. A list of species that may be planted along Raja Kaluves is furnished in Annexure-XIII.
f) Prevention of sewage inflow into the lake: Sewage treated to secondary treatment standards must only be allowed into the lake bodies. No raw sewage or trade effluents must be allowed into lakes bodies. Wherever possible, treated sewage must be made to flow through dense reed beds and/or constructed wetlands, designed in a manner that is both aesthetic, ecologically viable and with low maintenance. These reed beds/constructed wetlands aid in cleaning up/filtering the waters, improve local micro-climatic conditions, increase ground water recharge between the lake bodies.
8. Strategy for preservation of Bangalore lakes:
1) Lake area should not be diverted for any other purpose as lakes have an increased
and important role to play vis–a-vis lakes in rural areas, like ground water recharge, climate moderation, act as lung spaces, water for various purposes, urban recreation etc. The City has lost many important lakes due various diversions already.
2) Lake area is to be surveyed with total station as per the village map and records. Encroachments, if any, are to be removed. As part of survey, boundary stones in concrete are to be fixed in 3 to 4 corners of the survey, to facilitate easy future resurvey work of the lake as and when required. It is suggested to record Latitude & Longitude values of the corner stones so fixed by using Differential Global Positioning System (GPS) of sub-meter accuracy. It is relevant in the background of ever escalating land value in Bangalore city and consequent vested interests to grab public lands adjoining private lands. Geographical Information System (GIS) is to be established for the lakes of Bangalore City for planning and monitoring purpose.
3) Lake preservation is not limited to lake area itself, but very much dependant on catchment area and the drains that bring rainwater in to the lake. Raja kaluves, branch kaluves are to be surveyed and encroachment therein evicted. The buffer prescribed for primary, secondary & tertiary drains in valleys as per Zonal Regulations has to be religiously implemented, more so in areas which are not developed yet, to facilitate appropriate storm water drains, sewerage lines, inspection paths etc., as when the area comes up for development/urbanization. Advance action in this manner is imperative, if the unplanned development of Core area Bangalore City is not to recur in future.
4) The present norm of 30 mt buffer surrounding leagal boundary lakes is a must to preserve the lakes and if the buildings are allowed too close to lakes, it will affect the lake environment adversely. The buffer limits, needs to be reviewed and it is suggested to increase the 30 mt buffer progressively by 2mt per every 5 ha of increase in lake area beyond 40 hac. This will facilitate development of buffer surrounding the lake in the form of tree parks, walking path without reducing/compromising lake area for creation of such facilities.
5) Lake preservation has to be integral to Layout Development by BDA and Layout approvals by development and planning authorities like BIAPA, MICAPA, Nelamangala Planning Authority, Hosakote Planning Authority etc., as eventually these areas will be part of Bangalore city. BDA should not acquire lake area at the time of notifying the area for development and allot sites in the lake area as was done in many a layout development previously. Instead they have to properly get all the lakes, raja kaluves, drains surveyed and marked on the ground as per village records with boundary stones and make provisions for buffers as laid out in their norms. The area that has to be kept for parks as amenity in the BDA Layouts, can be earmarked surrounding the lake area, so that it serves the conservation of lakes and public recreation as well. Storm water drains and UGDs are to be laid out, before the sites are allotted, lest the problems of core Bangalore are bound to occur even in new areas.
6) Core operations like survey, removal of encroachments, fencing, watch and ward, clearing of blocked and encroached raja kaluves & drains, waste-weir repairs, desilting to the extent absolutely required are to be taken up on priority.
7) Effective Lake area should not be reduced by converting lake area into parks, children play grounds, widened bunds etc. The de-silting has to be minimized to remove only sludge portion with minimum depth near foreshore reaching maximum depth at the bund. The present saucer shaped de-silting should be given up as it is cost prohibitive and leads to huge bund making and creating storage capacity beyond the need. Saucer shaped deepening of lake bed will affect the wetland formation in the foreshore region of the lake, which is essential to filter the water that enters the lake and important from ecological point of view. Exception to this can be restoration of lakes, with adequate anticipated inflow during rainy season, where deepening is suggested keeping in view impounding more water to recharge the depleting ground water and to mitigate the flash floods.
8) Unless sewage entry is restricted, based on the experience of lakes developed so far, no lake improvement is to be taken up except survey, removal of encroachments, fencing and watch & ward. There is no point in de-silting and other developments, if lake continues to receive polluted water. Diverting sewage is not an option in the absence of other inlets into the lake to bring rainwater. Diverting sewage is leading to drying of lakes as in case of Doddabommasandra lake, Agara lake etc. BWSSBs action plan to separate the sewerage entry in to storm water drains directly and consequently in to the lakes will be in place only by 2014/2015. This being the case the agencies developing the lakesmay have to invariably go far a Sewage Treatment Plant for an individual lake/for a group of interconnected lakes in consultation with BWSSB to ensure that they fit into their larger plan of sewage treatment. Lake restoration is to be taken up based on lake series/subseries and not in isolation, to have better results and impact.
9) Some of the lakes of Bangalore are prominent for their ecology due to local and migratory birds, aquatic fauna and flora. Lakes of this nature are to be improved keeping this aspect in focus so that after the development lake is not subjected to increased disturbance in the area. Such lakes may be identified and notified under Wetland (Conservation and Management) Rules, 2010.
10) Annual field inspection by higher authorities of the custodian organizations and annual jamabandi of lake records by revenue department & lake custodian organizations are to be carried out.
11) Selected lakes are to be developed for augmenting water supply to city as the City can’t draw water from Cauvery beyond its allocation to the City, which it will exhaust once Cauvery water supply Stage IV, Phase II is completed by 2011. Sewage entry into the selected lakes has to be stopped totally and tertiary water treatment has to be installed.
12) Lake management committees have to be constituted with representatives from Resident Welfare Associations/NGOs.
13) Traditional users of the lakes like Dhobis/fisherman interests are to be taken care of. If lake is used traditionally for washing clothes, dhobi ghats are to be constructed when the lake is taken up for development.