Rainwater Tanks

In our country, rainwater downspouts are directly connected to the sewage system, creating an additional burden on the network during heavy flooding. Storing this clean water and using it when needed will not only meet the needs of citizens but also make the city more resilient to climate change. For this reason, the Izmir Metropolitan Municipality aims to include 5,000 buildings in the rainwater harvesting system with 5,000 polyethylene rainwater harvesting tanks to promote the widespread adoption and development of this practice in our city. The goal is to use the rainwater tanks included in the incentive system for purposes such as garden irrigation, car washing, or building cleaning.

Details
Yağmursuyu Depoları

Priority Criteria

To achieve the project's goals and provide more efficient services to the city, the rainwater tanks distributed should be placed in strategic locations. The following factors are important for the selection:
 
1. Rainwater downspouts that are directly connected to the city sewage system
2. Rainwater downspouts are flowing directly into the streets or the garden
3. Rainwater downspouts that come directly from the roof is not mixing with another source of water (such as from cleaning activities in the balcony etc.). This should be stated during the application
4. Installation area is in the “Flood Map” provided by the İzmir Metropolitan Municipality – Water Resources Research and Implementation Center
5. There is a suitable area for installing the tank
6. Routine roof maintenance is carried out

Installation Criteria

The polyethylene tanks included in the incentive system will have capacities of 1, 3, 5, or 10 tons. Applicants should make their selection based on the size of the roof area and garden. Since it may not be possible to collect all the water from roofs in existing buildings, partial storage can be done.

1. Rainwater tanks will be included in the incentive system by the Izmir Metropolitan Municipality, and the installation will be carried out by the citizens. 
2. After disconnecting the rainwater downspout from the sewage system and connecting it to the tank, a drainage pipe should be installed to remove excess water from the tank.
3. In the case of selecting a small tank, the diameter of the rainwater drainage pipe should not be smaller than the diameter of the rainwater downspout.
4. Having the installed tank close to the rainwater downspouts will reduce the installation cost. Therefore, it is recommended that the rainwater tank installation location be close to the rainwater downspouts.
5. The ground where the system will be installed should be flat. Elevating this ground to a certain level (20-50 cm) will provide convenience during water reuse. Otherwise, water can only be obtained through a hose, not a tap.
6. To prevent mosquitoes and other insects from entering the tank and to prevent contamination from the roof, a filtering unit should be installed by the applicant. These filters should be cleanable and made of suitable material with appropriate pore size.
7. The installed filter should be directly below the rainwater tank's inlet cover or on top of the rainwater downspouts.
8. The citizen performing the installation can add a leaf strainer filter to the roof for better filtration.
9. Rainwater tanks should not be used for drinking purposes. To ensure understanding even by children and citizen with limited literacy in buildings, a "NOT FOR DRINKING" label should be affixed to the tank surface with a logo.

Maintenance

• After the installation of the rainwater tank, roof and gutter maintenance should be carried out. During the initial installation, it is necessary to clean any pollutants that may come from birds or other living organisms on the roofs of old buildings.
• To prevent the accumulation of dirt on the roof, routine cleaning should be done before each winter, ensuring that the roofs are clean.
• To maximize the efficiency of rainwater collection, roof gutters should be periodically cleared of leaves and debris.
• The installed filters should be checked at least once a year to monitor for clogging and cleaned if necessary.
• If the harvested water in the tanks is not used, it should be emptied, and the storage of stagnant water for a long time should be prevented.
• The tank should be completely emptied once a year, and a thorough cleaning should be performed using pressurized water.

Monitoring

After the installation of the rainwater tank, the officials of Izmir Metropolitan Municipality can monitor the efficiency and quality of the rainwater harvesting system. They can examine the water quality and filtration systems.