rollinghills rainwater plan

8/16/2019 RollingHills Rainwater Plan

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Case Study:

Rainwater Harvesting in

Gated communitiesProposed water management plan

Rolling Hills, Gachibowli, Hyderabad

May 2016


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Highest

point

Lowest

point

slope

ROLLING HILLS(110 villa community,

Gachibowli)

2 live borewells

1 partial borewell

2 defunct bores

•14 acres property

• 110 houses

• 30% building space

• 2 large parks

• Natural slopes to one end

• Rainwater flowing into

gates from outside

• Each home’s terrace

water let out on road

Rooftop, roads and

sidewalks’ water on

road. Total non-seepagearea is 50% of total

14acres ~= 30k sq mt

1cm rain ~= 300K litres!!


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The water challenge:Lots of rain. But no water in summer!• 110 homes. Summer water shortage

• Dependent on city water and 2 borewells• Until 2015 no effective recharging happening• Summer water shortage, needed to buy 10-30K litres per

day

• Rains, 300,000 litres of water per hour• 14 acres @ 1cm rain (peak rains can be 3-4 cm/hour)• After absorption in gardens & unpaved parts of individual

villas

• Rainwater flows like a river• Rain water from each house let onto road. At lowest point

water flows like a river into a massive storm water drain• Often causing flooding

• Flowing out into a poorly engineered neighborhood stormwater system

A harvestingsolution was

imperative!!

For the whole community.Comprehensive solution


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Multi Layered strategy

Individual houses

Rooftop collection,filter,store in sump

Overflow let ontostreet

Streets outside houses

Near each house,a small groundrechargeharvesting pit

IntersectionsLarger RWH pitswith an 30 feetinjection bore

Near Borewells

RWH pit with a200 feet injectionbore

Water fromnearby areasdirected to nearborewell

Lowest point

Built water mini-dam structure,and let water from

here into a largesand filter

From filter onto adeep (1000 feet)defunct bore withlarge absorptioncapacity


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How?

Source: http://www.kscst.org.in/rwh_files/rwh_rooftop.html

https://www.hyderabadwater.gov.in/en/rainwater/aboutus.aspx

Speed bump

Deep

Borewell

Sand/stone

filter

IntersectionsLarger RWH pits with an 30 feet injection bore

Near BorewellsRWH pit with a 200 feet injection bore. Water from

nearby areas directed to near borewell

Individual housesRooftop collection,

filter,store in sump

Overflow let onto street

Lowest pointBuilt water mini-dam structure. Let

water from here into a large sand filter.

From filter onto a deep (1000 feet)

defunct bore


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Further plans

1. Complete rooftop filters forall homes

2. Road pavement tiles (outsideeach driveway)

3. Side walks harvesting

4. Roof top gardens

2

3

4


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Key results

• Even as only partially complete, in a bad summer after failedmonsoons, when most borewells in the city and around thecommunity dried up, the two borewells yielded good water(touchwood )

• With remaining works underway in summer of 2016, water going intoexternal storm water drains will be significantly reduced

• Hoping the ground (and deep aquifers’) recharge from the colony will

help the whole extended neighborhood filled with very dense highrise apartments


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Thanks

Prepared for Save10KBores campaign!

rollinghills rainwater plan

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