Rain Water Harvesting System

 

 

Rain Water Harvesting System

What you should know (basic concept) 

 A rainwater harvesting system basically: 

•  Collects rain from your roof gutters
•  Sends it through a filter (to remove leaves/dirt) 
• Stores it in a tank/barrel 
• Uses it for non-drinking purposes 

 In Malaysia, it works very well because rainfall is high (~2,500 mm/year) . 

 Common uses: 

•  Water plants / garden 
• Wash car / floor / outdoor area 
• Toilet flushing (slightly advanced setup) 

 What you should prepare 

• Basic components (small DIY system) 
•  You can start very simple: 
•  Storage tank / drum (200L – 2000L) 
• Plastic water tank, IBC tank, or rain barrel 
•  Gutter connection / downpipe diverter 
• Directs rain from roof into tank 
•  Filter / mesh screen 
• Blocks leaves, insects, debris 
•  Tap / hose connector 
• For easy water use 
•  Overflow pipe 
• Prevents flooding when tank is full 
•  Optional upgrades (better system) 
• First-flush diverter (removes dirty first rainwater) 
• Pump (if you want pressure for washing) 
• Multiple tanks linked together 
• Mosquito-proof lid (important in Malaysia) 

 Installation considerations (important)

✔ Roof type matters 

• Metal & tile roofs = good 
• Avoid collecting from dirty/paint-flaking surfaces 

✔ Tank placement 

• Near downpipe = cheaper piping 
• Ground level = easier maintenance 
• Elevated = better water pressure (optional) 

✔ Mosquito control (VERY important in Malaysia) 

• Always cover tank tightly 
• Use mesh filters 
• Avoid stagnant uncovered water 

✔ Maintenance 

• Clean filter: every 1–2 months 
• Flush tank: every few months C
• heck gutters for leaves 

 Cost in Malaysia (realistic range) 

•  DIY basic setup 
• RM100 – RM500 (drum + pipe + basic fittings) 
•  Example: garden watering system only 
•  Small proper system (recommended starter) 
• RM1,500 – RM5,000 
• Includes: 
• 500L–2000L tank 
• Proper diverter + filter 
• Basic installation 
• Good for: Garden + car wash + light household use 
• More advanced home system 
• RM5,000 – RM10,000+ 
• Includes: 
• Larger tanks (3000L–10000L) 
• Pump system 
• Filtration for indoor use (toilet/laundry) 

What affects cost most 

• Tank size (biggest cost) 
• Pump & filtration level 
• Plumbing distance from roof to tank 
• Whether it’s DIY or contractor-installed 

Simple recommended setup for a landed house (best balance) 

•  If you want something practical: 
• Start with:
• 1000L–2000L tank 
• Gutter diverter + mesh filter 
• Hose outlet 
•  Cost: around RM500–RM2,500 DIY / semi-DIY 
•  This already gives noticeable savings on water for gardening and cleaning. 

Common mistakes to avoid 

• No mosquito protection (big issue in Malaysia) 
• Tank too small (fills too fast, wastes rain) 
• No overflow pipe (causes flooding) 
• Using dirty roof without filter