Storm Water Drains and BBMP budget

1 September 2008 - 9:54am — Ravi_D

Vehicles, animals and now people floating in rain water pools - Sound familiar?

Deja vu. Examples: Today's Deccan, Friday's Deccan

For once, let us forget what happens with the money spent. But what if the allocation was never spent? Attached PDF is an extract from BBMP's budget document.

Rs 37,063.33 lakhs - 07-08 budget estimate; 8,349.33 lakhs - 07-08 revised estimate (Spent ?)

BBMP's allocation for 08-09 is lower than 07/08. If the same trend continues, and Bangalore's current citizen lethargy remains, expect worse come next monsoon.

This is nothing new. First allocation was in 2002-03. See this Hindu article from 24/Apr/07. And this one from 09/May/07.

Rains, drains, flooding and misery is a real story. You like it or not, this will repeat next year, and the year after and the year after - Unless we do something about it. I know spending money does not solve the problem, however, it is a good indicator of our willingness to tackle the problem at least.

Thanks,

Ravi

Attachment	Size
Budget Estimates for 2008 - 2009 (Storm Water Drains).pdf	51.24 KB

Comments

what exactly is "revised" estimate?

silkboard - 2 Sep 2008 - 9:23am

Good digging Ravi!

See these on page "JNNURM works"

Hebbala Valley - budget estimate 7390 lakhs, revised estimate Rs 2122 lakhs
Koramangala Valley - Rs 4460 lakhs, revised estimate Rs 587 lakhs
Remodelling of drains in 3 CMCs, estimated Rs 6000 lakhs, revised Rs 1477 lakh
And this one is the most dramatic
- Separation of sewerage from SWD, BBMP share to BWSSB - estimated Rs 4000 lakhs, revised Rs 2.9 lakhs only !!

what exactly is revised estimate - actual money spent? Was this because they couldn't spend

as the planning (original estimate) was poor
or they simply didn't finish the work they had planned?

Perhaps we should be happy that they didn't drain all the "budgeted" money. Corruption could have made that a possibility, right?

JNNURM

tsubba - 4 Sep 2008 - 3:47pm

I think, what hapenned is, in the first year they got money from JNNURM. But, right now JNNURM funds are frozen because there is no elected body. Until there are elections to local bodies no NURM funds. I am very interested in figuring out what they mean by remodeling of the valley. thats a very grandiose title for a project. biblical/bhageeratha proportions only remodeling is. wondering what earth they are moving, why and how and against what designs.

All earth is basically a drainage system.

tsubba - 6 Sep 2008 - 7:42am

I have always maintained that BWSSB should be incharge of storm water drains. Its reassuring for a layman when his intuition agrees with insights of experts like S. Vishwanath

Surprisingly, recent evidence suggests that it rains more in the city and slightly downwind than in the regional rural periphery. This is according to a study by NASA scientist Marshal Shepherd. The urban heat island effect, where cities are warmer than their surroundings and which causes the build-up of rain clouds on the city; pollution, which allows rain to coalesce around dust and oil particles; and the wind-break effect of cities, which causes the clouds to discharge on the cities, all seem to contribute to this phenomena. Bengaluru needs to prepare for more rain than average and higher intensity rains at the same time. Cities also increase runoff as more and more soft agricultural and fallow areas get built upon or paved. From a small well-mulched site, hardly 10 per cent of the rain falling will runoff as storm water. However, build a house on the same site and pretty much 90 per cent of the rain falling will runoff as storm water. Buildings increase runoff tremendously in the Bengaluru context and the storm water drains have to cope with this increase. Waste management Solid waste management is crucial to flood management since most of the uncollected garbage will end up in the lowest area, usually the storm water drains, choking them and reducing their ability to carry storm water out. Tanks and lakes which collected surplus water and recharged the groundwater or dissipated it slowly are on the decline. These are built up, like the ISRO headquarters built on an old tank bed. They then become prone to flooding or transfer the flood problem downstream. The network of tanks and the valleys and drains connecting them are in a bad state of management with encroachments on several of them. With no institutional approach to manage the tanks and the valleys, little is done except during the flood event itself to ensure that the channels flow freely and that the tanks are not encroached upon. Traditional storm water management techniques simply collect the rain water and funnel it across the city downstream. Newer methods combine traditional approaches with new ones such as Sustainable Drainage Systems (SUDS). It employs a range of natural processes to purify urban runoff. Removal of sediment, bio-filtration, biodegradation and water uptake by plants all help to remove pollutants. Vulnerability maps of areas prone to flooding need to be prepared for citizens to become aware of the choice they make for where they live. Rainwater harvesting Even as the Government is working towards making RWH mandatory in the coming days for the city, the system has one of the best potentials to replenish ground water, improve its quality, provide supplementary water for domestic requirements and mitigate flooding. If every building in Bengaluru can store or recharge 60 mm of rain in a single day it should be possible to mitigate the effect of almost every flood except the rare. This means that a 100 square metre roof area will need to store or recharge 6,000 litres of water. Zones with the best possible recharge and zones with the best possible storage need to be identified in the city and steps taken to encourage people to go in for rainwater harvesting. A recharge well of 3 feet diameter and about 20 feet depth can send in up to 12,000 litres of water into the ground in a single day, provided lithological conditions are favourable. The city needs many such recharge wells in the catchment area of critical flood zones to detain flood waters and top up the aquifers instead of surface flow flooding. At the broader scale, tanks and lakes need to be networked and managed as retention and detention structures. With rainfall prediction accuracy being developed, tanks have to be linked to catchments and kept ready to hold the maximum water to dampen peak storm events. A deslited tank in Bengaluru can recharge up to 11 mm of water every day while an undesilted one can recharge hardly 1 mm. Desilted tanks can recharge aquifers quickly, lower the surface water levels and be in a position to function as flood mitigators. Full tanks are not good at dampening floods.

Actually ravi, if you meet sudhira on saturday, you should ask him about mapping, storm water drains and prediction systems that Vishwanath talks about here. He has a PhD in the area under Prof. Ramachandra of IISc.

SuDS

tsubba - 6 Sep 2008 - 8:04am

From Wikipedia Sustainable Drainage Systems (SuDS), sometimes known as Sustainable Urban Drainage Systems (SUDS)[1], are designed to reduce the potential impact of new and existing developments with respect to surface water drainage discharges. The idea behind SUDS is to try replicate natural systems that use cost effective solutions with low environmental impact to drain away dirty and surface water run-off through collection, storage, and cleaning before allowing it to be released slowly back into the environment, such as into water courses. This is to counter the effects of conventional drainage systems that often allow for flooding, pollution of the environment - with the resultant harm to wildlife - and contamination of groundwater sources used to provide drinking water. The paradigm of SUDS solutions should be that of a system that is easy to manage, requiring little or no energy input (except from environmental sources such as sunlight, etc.), resilient to use, and being environmentally as well as aesthetically attractive. Examples of this type of system are reed beds and other wetland habitats that collect, store, and filter dirty water along with providing a habitat for wildlife. Originally the term SUDS described the UK approach to sustainable urban drainage systems. These developments may not necessarily be in "urban" areas, and thus the "urban" part of SUDS is now usually dropped to reduce confusion. Other countries have similar approaches in place using a different terminology such as Best Management Practice (BMP) and Low Impact Development in the United States. SuDS use the following techniques: * source control * permeable paving * storm water detention * storm water infiltration * evapo-transpiration (e.g. from a Green roof) A common misconception of SUDS systems is that they reduce flooding on the development site. In fact the SUDS system is designed to reduce the impact that the surface water drainage system of one site has on other sites. For instance, sewer flooding is a problem in many places. This happens when flows entering a sewer exceed its capacity and it overflows. The SUDS system aims to minimise or eliminate discharges from the site, thus reducing the impact, the idea being that if all development sites incorporated SUDS then urban sewer flooding would be less of a problem. Unlike traditional urban stormwater drainage systems, SUDS can also help to protect and enhance ground water quality. ----------------- The critical aspect is ofcourse to generate popular and political awareness about the absolute necessity of this. Folks inundated in water can perhaps appreciate the criticality of all this. Important thing is to get the local politician and the concerned officials to start talking about this. I am pretty sure within Bangalore there is solid knowledge base to get all this started. I am pretty sure if BWSSB is serious about this, they can fund a researcher at IISc to take a serious look at this. Folks at KI, roped in a professor to look into the effect of master plan on koramangala valley. Why cant the BWSSB do the same? ella private consultant-e aagbeka? nammoor jana aagolva? Whatever remodelling they are doing is fine. But given source side constraints in Bengaluru, we really need second generation systems not more of the same.

About relativey little less rains in periphery

silkboard - 6 Sep 2008 - 9:06am

May be true. More than few times, we have noticed that while it was raining and jayanagar, till Jayadeva circle, almost till silkboard junction, it wasn't in whitefield. The reverse observation is much less - outnumbered 1 to 5.

Have you see any such rainfall micro-map of Bangalore Metro Region? I am sure nobody has tried to map to ths level yet, but this should be agood project for our local university's relevant department (geography?)

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