Showing posts with label deweeding. Show all posts
Showing posts with label deweeding. Show all posts

Sunday, July 8, 2018

Family gardening day July 7th - Report

A lovely morning at the lake started with 2 adults and 1 child assembled at 9:30 am at the gazebo to do their bit for their lake.We, the PNLIT members, wondered what tasks we can do with just 3 of them, but 5-year-old Avani solved our problem as she was all for deweeding and  wanted to remove "bad" plants first, like she did last month.

So off we went with our mini trowels, shovels and rakes and started pulling out the "bad" ones. By 10 am we were 7 adults and 13 kids de-weeding the sidewalk area, raking the dry leaves and pushing them around the trees, shoveling the soil and shearing the hedges. It was a pleasant surprise to see what 13 kids can do when they get to doing!


A loud shout-out to the parents who brought their kids and their friends to work at the lake today. We hope other parents and kids will also join us in the family gardening day on the first Saturday of every month. Next one will be on Aug 4th


Sapana
Gardening activity volunteer











Saturday, April 23, 2016

Green to Clean

We are delighted to tell you that finally our lake is showing, almost, its true glory! The alligator weed which had covered most of the entire expanse of the water has been removed thanks to funding received from Deloitte Shared Services India Private Limited. 

27-Mar-2016 Before deweeding

18-Apr-2016

Their CSR support enabled us to hire Yellappa and his team of fishermen who began work from 3rd April and completed it on the 20th. They were an excellent group of workers who did not let anything deter them. Not the heat nor the water snakes nor the tangled shoots of the alligator weed which had spread like a large thick sheet over the water. 

Deweeding in progress

Indeed, except for us trustees and a few regular visitors to the lake, almost everyone who spoke to us doubted if there was any water at all in the lake. But little by little the water started to show as the men cut the weed deep down in the water and hauled the strips along for their colleagues to pull onto the land.They piled it along one side of the lake bed which is higher and still dry land. And what huge heaps they made! BBMP helped us dispose these off. They have sent a couple of JCBs to dig deep pits in the lake bed and tractors to fill the pits with the waste. 

We've documented all these through photographs, a selection of which you can see here. Yesterday evening, as if in celebration of Earth Day (22nd April), Yellappa released over 1200 fingerlings in the water. The four species of fish released included the Grass Carp which feeds on aquatic plants. We hope it lives up to its name and keeps the weeds under control. 

22-Apr-2016 Fish being released into the water

It is for the first time since 2009 that the lake has some water at this time of the year. (See here for pictures through the past few years.) This is because rather than depend on the unreliable monsoon, we have treated waste water from South City STP feeding the lake. What a welcome sight it is!     

21-Apr-2016

While we can now breathe easier than in the past few months, our work isn't done yet. We need to ensure that the lake remains free of all invasive aquatic weeds and implement measures to improve the quality of the water. 

It has been a long haul for both the lake and us, trustees, who are driven more by passion than by qualification or prior experience in conservation. We would not have been able to come this far without the help of all our supporters, donors and volunteers. Among many others, we would like to thank especially BBMP (lakes), South City apartment owners' association, Fisheries Dept, and Yellappa and his men. Above all, our heartfelt thanks to Deloitte Shared Services India Private Limited, our CSR Partner in this "Clean Puttenahalli Lake Project". 

- Usha Rajagopalan

Monday, November 23, 2015

Can you get us CSR fund to clean our lake?

Dear Friends, 

Even if you do not visit our Puttenahalli lake too often, our updates would tell you of the trials, tribulations and thrills we experience as citizen custodians. We are much more than a mere watchdog body. Slowly but surely we have been taking several steps to improve the quality of the lake and sensitizing the locality about its importance. 

The rain and regular inflow of excess treated water from the South City STP are increasing the level beautifully in our lake but growing profusely along with it is the alligator weed (Alternanthera philoxeroides; honagone soppu). This is a weed that grows lush on land and in water. Just a bit is enough for it to multiply! We need to remove it before it covers and kills the lake. The amount we need for this is between Rs. 10 to 12 lakhs. To ensure that the weed doesn't recur we want to enter into an annual maintenance contract for at least three years with the lake cleaning team. This will cost about Rs. 3 lakhs a year. 

While BBMP is supportive and in fact, they cleaned the lake only in March this year, they do not have the funds. Even if they do, procedural delays will lead to the weed growing some more. We need corporates to pitch in through their CSR. Can you get us CSR fund to clean our lake? 

Indeed, do please share this request with as many of your friends and contacts as you can. Together let's tackle this menace. After working so hard to rejuvenate the lake we don't want to surrender it to an obnoxious invasive weed!

Many thanks
Regards
Usha
Chairperson, PNLIT
mob. 72597 22996


Tuesday, June 10, 2014

Water in the lake again!

The recent heavy rains in Bangalore have resulted in quite a bit of water finding its way into Puttenahalli Lake, quenching the thirst of the cracking lake bed. Something like a full bottle's water getting poured into one's throat, after a long harsh summer outing. 

As a part of the summer regimen, workmen have been deweeding, and a lot of the water weeds have been taken out. The green around is looking lush. 

For those who do not live in the Puttenahalli Lake vicinity, here are some recent pictures.

6-Jun-2014 Before completion of deweeding

6-Jun-2014 Deweeding in progress
​9-Jun-2014 Lake after deweeding
Pics by Nupur Jain. More pics can be seen here.

Friday, September 27, 2013

An exciting afternoon at the lake!


Yesterday, some of us spent a delightful afternoon at the lake releasing some 3000 fish (fingerlings) into the lake. Fisherman Yellappa whom we've hired to remove the alligator weed from the water bought three species - Rohu, Katla and Glass Carp from the fisheries department. The Glass Carp is a herbivore and will nibble the aquatic weed.  All three are fresh water fish and common species, popular among fish eaters but the ones introduced today are specifically to attract birds and not for human consumption!

The fish

Kumar releases the fish

The specs are fish!

We also tried out our inflatable boat, that we got from a well wisher last year. Since the water level increased only from this monsoon, we were able to use it only now. Yellappa and others rowed a short distance in the water. They returned safely all right but, though we have life jackets, the rest of us preferred to remain on firm land! The boat is specifically for periodic monitoring of the waters, and to assist in deweeding. Boating is not on the agenda!

Inflating the boat

Yellappa 

Next steps:
* We've bought casaurina poles of different lengths which Yellappa's men will plant at various points in the lake. These will serve the dual purpose of indicating the level of water and as a perch for the birds. 
* We plan to introduce Guppies into the water soon. Guppy is a popular freshwater aquarium fish which feeds on mosquito larvae.

For those of you living in the neighbourhood - if you'd like to be a part of this excitement, please email <puttenahalli.lake@gmail.com>;. We'll inform you about planting the poles, introducing the guppies, and anything else.

Usha

Sunday, August 18, 2013

Volunteers this weekend

On both Saturday and Sunday, there were about ten volunteers (including a few school children from Kumarans on Sunday) who did a clean-up of flower patches and other de-weeding. One of them, Rohit, came all the way from Marathahalli.  

Volunteers on 17th Aug 2013 (Pic: Sanjay M)

More pics by Sanjay can be seen here.

Thursday, August 1, 2013

Grappling with water weeds

If we think that with fencing the lake area to prevent further encroachment, planting trees and bushes and nurturing them, eliminating sewage, and getting more rain water into the lake, we have saved the lake, we're in for a surprise. That is just the beginning!  

It was last August when a gentle green carpet started spreading itself over the dormant waters of Puttenahalli Lake. PNLIT trustees brought this to the notice of a few experts who said it could be a form of algae, and that the best way to get rid of it was to get more clean water into the lake. With a scanty monsoon last year, very little water entered the lake, and with rain water being the main source of water for the lake, there was little we could do. It was several weeks later, when one of the experts actually visited the lake, that the green carpet was identified as Salvinia molesta, an invasive aquatic weed that thrived in water, and was capable of doubling itself in a couple of days. No wonder that during the time since we noticed it, to the time we positively identified it, the surface of the lake was totally covered, barring a couple of patches. Most likely, the Salvinia got into the lake with the rain water. 

Sept 2012, a carpet of Salvinia on the water (Pic: Usha Rajagopalan)

We knew that many of the fish under the water were still alive as on a few occasions we caught some boys with their fishing bounty. Reason enough for the purple heron and swamp hens to stick around, but many other birds that had made the lake their home quietly left. They were probably not getting enough food and we knew that they would come back when the situation was better for them. The fish and other water creatures did not have a place to go to, so the oxygen depletion caused by the Salvinia would affect them and they would be the ones to suffer. Till the time the Salvinia was removed, keeping some area of the surface free of Salvinia would help the oxygen level.

Clearing out the Salvinia was the priority. Manual (mechanical) removal was the most obvious method. PNLIT trustees got in touch with several agencies and contractors. MEG (maintaining Ulsoor Lake) and the Fisheries Department said they were not in a position to help. Those contractors who visited the lake gave us quotations in the range of Rs 1.65 lakhs to Rs 4.50 lakhs for what they said would be 15-20 days of work for 25-30 workers. The Salvinia itself is easy to remove, as we experienced with volunteers. Its roots are only on the water's surface, but one is limited by one's reach. In very shallow waters, one would need to get into the water to reach it. Where there is sufficient depth of water, a coracle or boat would help. Labourers usually get into the water after sprinkling lime on the water to kill the water leeches and rubbing themselves with Honge oil to keep the live ones off. They use bamboo poles and nets to rope in the weeds. Then the weeds need to be moved from the water and marshy areas to a place where they can dry out. So deweeding, the way it is done, is very labour intensive, and as we found out, very expensive.

Prasanna and OPR visited Madiwala Lake to see how weeds were controlled there. Water hyacinth is the dominant weed here. The lake has a fishing contractor, who harvests the fish, and the responsibility of deweeding has been given to him. As he has an economic interest in the lake, deweeding is important for him, and as the lake is very large, deweeding needs to be done on a daily basis. His team spends each working day doing both fishing and deweeding. The labourers apply Honge oil and get into the water to push the weeds towards and onto the shore. Then a crane is used to scoop it up and pile it away from the water. Where it is deep, they take a boat right into the thicket of the weeds, and others on the shore pull the boat towards them using a rope. This brings the boat along with a big bunch of weeds.

We were fortunate that the Salvinia infestation happened at a time when we still did not have a lake full of water. The lack of rain was a blessing in disguise. It gave us a chance to not panic in despair but instead research and experiment a bit also.

Research on Salvinia and weed control indicated a few options of removal. Apart from the manual removal we had considered, there was chemical removal – using chemicals/ herbicides which we decided not to explore because of the possible effect on the water/ aquatic life. Biological treatment using the Salvinia weevil was another option which we kept in mind.

Bruhat Bengaluru Mahanagara Palike (BBMP - which has the responsibility of large-scale deweeding at Puttenahalli Lake), in the meantime said it would undertake to do the deweeding along with another lake – in a couple of months. Being dependent on water, we knew that as summer approached, the Salvinia would dry out. So a couple of months would not be too bad. 

We realized that whichever method we used to remove the Salvinia, expecting total removal was impractical. We needed to have a proper regimen in place so that post removal, whenever the Salvinia was seen it could be attacked promptly. We decided to invest the money we would have spent on deweeding on proper equipment. In many countries (such as USA, UK, Australia), lake maintenance equipment is abundantly available, and this increases efficiency while reducing dependence on labour. We did a lot of online research and I had a few interactions with lake equipment dealers in the UK and USA, to get advice and ideas.

On our request, Gautam Aggarwal, a well-wisher from London, bought and carried for us, a very useful rake called the Aspen Lake Rake, which can be used to reach far out from the shore. He also got us an inflatable boat that we haven't had a chance to use yet. Kavita Arora, another well-wisher, arranged for a couple of pairs of hip-boots from London to reach us in Bangalore. We designed a few other floating aquatic rakes that we couldn't buy online and got them fabricated. We also got approved life jackets from a supplier in Mumbai. All this equipment is proving to be useful at the lake.

Aspen Lake Rake, from UK (Pic: OP Ramaswamy)

Serated tooth rake, fabricated in Bangalore (Pic: OP Ramaswamy)

Long tooth rake with float, fabricated in Mumbai (Pic: Arathi Manay)

By the beginning of March, with the water level at its lowest, most of the Salvinia had turned from green to brown. Over a couple of weeks, PNLIT volunteers helped in clearing the lake bed. It was a massive effort and this spurred the BBMP to join the action. The marshy and more difficult areas were handled by the BBMP contractors and the JCB. While a lot of the Salvinia was moved out of the lake bed and composted, the volume was so huge that we had to find another option that ensured we handled this in the lake premises itself. As the monsoons were still a couple of months away, it was decided to dig a trench in the lake bed and bury the desiccated plants.

9-Mar-2013 Volunteers clearing Salvinia from the lake bed (Pic: Usha Rajagopalan)

After clearing out all the visible Salvinia, over the next few weeks in April and May, we were always on the look out for its reappearance. With the rains in May the birds started coming back! The Salvinia did reappear in small patches and we got it removed each time.

4-Apr-2013 Fresh Salvinia (Pic: Nupur Jain)

30-May-2013 Scooping out new Salvinia patches (Pic: Usha Rajagopalan)

After a few times of doing this, Usha got in touch with Dr Ganga Visalakshy from the Indian Institute of Horticultural Research, Bangalore and Dr Lyla K. R., from the Biological Control Unit, KAU, Thrissur regarding the Salvinia weevil. After discussions with them, we decided to try the weevil to control the Salvinia. The weevil eats only Salvinia so other plants will remain unaffected. Our well-wisher Ramani Ramasubramaniam carried the weevils from Thrissur and they were released into two small infested areas in June. When the Salvinia turns yellow, it means the weevil is at work. Normally the weevil spreads over to different parts where Salvinia is present, provided there is no obstruction in its path. Subsequently, we got another lot of the weevils, released them into new infestations, and are now keeping the weevil in stock. 

3-Jun-2013 Releasing the Salvinia weevil into a small infestation.
Alligator weed in the foreground. (Pic: Usha Rajagopalan)

While the Salvinia seems to be under control, we now have another "weedache". The Alligator weed has always been present in the lake. During the summers, we've seen it dry out on the land, but being amphibious and very hardy, it has never died out. In recent weeks, with more water in the lake, it has been crawling all over the water. With the ability to grow from a small piece, the Alligator weed is sure to keep us on our feet! We are now exploring how best we can use the equipment we already have and establish an efficient way to keep it under control.

We've also noticed what looks like green algae, supposedly caused by nutrients in the water, and are looking at tackling this too.

29-Jul-2013, Looks like algae (Pic: Usha Rajagopalan)

Once there is more water in the lake, we can look at means to aerate the water (maybe through fountains). A pedal boat to monitor the lake (pedaling will result in aeration) would also help. Aeration would increase oxygen supply to the lake and discourage weeds. Also, as the trees grow, their shade would hinder weed growth.     

For the long term

As more and more lakes are taken up for maintenance by citizens, we need to find an effective, efficient, yet economical way to handle water weeds. The BBMP/ BDA/ LDA have been using traditional labour intensive methods that require substantial budgets. It would be difficult for citizens' groups to get labour and to support such investment.

It may be worthwhile for the government agencies (or any private enterprising people) to invest in small water-weed management tools (that are not available in India but used extensively abroad) and larger weed harvesters/ pullers (either imported or Indian), that can be sold/ lent out to those managing lakes. With weed control set to be a major element of lake maintenance, a proper weed management agency (governmental or otherwise), that can help lake caretakers in devising strategies for effective weed control may become necessary.  

For those interested in knowing more about weed control, www.weedersdigest.com is an informative site. With the right tools and equipment, weed control could be as easy as pie!

Eco-Harvester (priced around Rs 30 lakhs) enables efficient weed control 
by a single person (Pic: weedersdigest.com)

Wednesday, April 24, 2013

An opportunity to reap the benefits of gardening

People who participate in community gardening have a significantly lower body mass index (BMI), as well as lower odds of being overweight, than their non-gardening neighbours and siblings. This is according to a study by Dr Cathleen Zick (Professor of Family and Consumer Studies) and her colleagues from the University of Utah, USA, published on April 18, 2013 in the American Journal of Public Health (AJPH). 

The study concluded that "Community gardens may be a valuable element of land use diversity that merits consideration by public health officials who want to identify neighborhood features that promote health." More details of the research can be found on the website of AJPH and the news report in The Daily Utah Chronicle.

While the above study was restricted to adults, it would not be incorrect to extend the benefits of gardening to children too!

Volunteers on 13th Apr 2013 (Pic: OP Ramaswamy)

If your child is inclined towards gardening, here's an opportunity for him/her to spend one hour everyday in a pleasurable activity during the summer holidays. PNLIT is looking for children (age 10 and above) to take care of the flowering plants in the garden at Puttenahalli Lake. Let them discover the magic of nature! They will have to come daily at about 4 p.m., do some deweeding and watering of the plants. 

Please contact Mr. O P Ramaswamy at opr.sulo@gmail.com.

Saturday, April 20, 2013

Volunteers' weekend

What a morning it was today! About 15 employees from Adobe, office at Dairy Circle, joined our resident volunteers and some children to create magic in a span of less than 4 hours. From 7.15 a.m. to 11 a.m., everybody spread out, formed teams and accomplished their assigned chore quickly, beautifully. 

These were the jobs they did today:
- Sand papered and painted four dust bins 
- Cleared out the rubble and waste along a stretch as preliminary to setting up a flower border. Dug a trench about one foot deep and nearly three feet wide. With the stones and mud, they made a bund along the fence, This needed quite some effort because the ground was rock hard. 
- Collected and made a pile of dry waste. 
- Vinay and Hariharan planted stakes for some trees which were growing tall and lanky. 
- The duo moved on to clean a silt trap. 
- Once done, they moved on again to fix a hollow pipe into the ground into which the bar of the garden gate latch would fit in snugly. We found that someone had pushed open the garden gate, hence this precaution.
- Four children plucked out weeds from the garden.
- Two others painted the smaller dust bins on the inner grill, a bright orange. These two were on a visit to their uncle's during the summer hold. 
- Restless for more work, Adobe volunteers offered to paint another two dust bins on the coconut grove side. One had been burnt by miscreants and was looking quite an eyesore. By the time these volunteers finished, the dust bins were looking as bright and cheerful as the painters themselves.



Sun or no sun, the enthusiasm of the volunteers, residents and visitors, was truly incredible. While leaving they asked if they could come and work tomorrow as well but my friends at PNLIT and I are pooped just watching them work in the hot sun. WE need a break tomorrow.

So all, please note - NO Volunteering tomorrow (21st Apr 2013)!! We shall inform you of the next session. Watch this space! :-)

Volunteers, there's only one word to describe you - amazing!

Usha


Sunday, April 7, 2013

This weekend's gardening

I guess the heat was too much and not many volunteers turned up this weekend. Those who did brave the sun did a wonderful job though. Yesterday, 6th April, some eight of us were scattered on the lake bed, bent over or squatting on the ground. We were searching for lurking bits of the Salvinia between the cracks and under stones since even a teeny bit is enough for it to sprout and cover the water in no time. 

Fresh Salvinia spotted earlier in the week (Pic: Nupur Jain)

Searching for Salvinia (Pic: Usha Rajagopalan)

It was back breaking work all right but we didn't realize just how much Salvinia we had collected till we saw how OPR had got it packed into a plastic sack and filled a big plastic bucket. If ever we were happy to see a plant browning and dying, it was the Salvinia. :-)

Their enthusiasm soaring high, Arvind Venkatadri from Brigade Millennium, Shankar Iyer from South City and Grishma from Jayanagar 4th block started work as early 6.15 a.m. this morning. Each working in his/her space, the only time they got together was to come out after a good one hour or so. By then, the other volunteers were assembling, ready to start work. 

We decided to water our little garden near the Gazebo and pluck out the weeds. A few women walkers saw us at work and joined us. How gratifying it is to know that more and more people are beginning to accept the lake as their own and are slowly taking a little responsibility for it.  

Working in the Gazebo Garden (Pic: Usha Rajagopalan)

As the number of volunteers was less, we were not able to do some other chores such as painting our new dust bins, clearing the front (near the cycle stand) and making it ready for planting, etc. So those who had intended to work at the lake this weekend but were unable to, join us next weekend! Those of you who have never worked in a garden, come and try it out. Get your kids along as well. Have gardening fun next weekend at our Puttenahalli Lake.

Usha