Rainwater harvesting, Composting & Food waste

The need for rain water harvesting solutions is increasing in our area and in other areas in Dublin

In the last number of years the waste water system in the estate has been overwhelmed and there has been some very limited flooding events in a few areas within the estate, however I do not believe any houses have been directly affected 

A proposed solution 

• Implement water butts on housing stock for rain water harvesting (1000 liters, in some cases 2 x 1000 liters)

• Implement rain water planters for housing stock that can also store approx 400 liters of water during a rain event

Extra Information & research papers 

• https://thewaterforum.ie/app/uploads/2025/04/Water-Forum-CBA-Report-28.03.25.pdf

• https://rainman.ie/wp-content/uploads/Rainwater%20Harvesting%20Pilot%20Project.pdf

• https://www.thewaterforum.ie/app/uploads/2022/02/A-Framework-for-Improving-Domestic-Water-Conservation-Report.pdf

• https://www.dublincity.ie/sites/default/files/2021-04/a-how-to-guide-to-rainwater-planters-english.pdf

• https://www.understory.ie/projects

• https://www.greenkite.ie

Analysis to be carried out in our area 

• Identify any households that have already installed water butts or rain water planters and obtain some feedback on them 

• I would like a rain water gullie rain sensor installed in one of the gullies in the estate that has over flowed

• I would like to obtain a few rain water flow meters to be placed on a few down pipes of to measure the amount of water going to the drain during a rain event. This information with other data can be used to get an accurate picture of the total rain water that went to the drains accross all 600 houses in our area for each large rain event 

Composting & food waste (funding can also be obtained for this type of initiative)

• Supply composting bins of various size for garden waste and food waste 

• Supply small food waste bin

 Benefits that these types of solutions can provide

• Reduction in rain water getting to the main drainage system during large rain events

• Water to use on your garden during hot periods and in some cases hose pipe bans 

• Use food waste and garden waste to generate compost 

• Increase the value of a house holders property 

• Aligns with DLRCC climate program etc 

• Processing 150000 liters of rainwater during a rain event costs Uisce Eireann approx €400 euros, so if there are 10 rain events per year where 150000 liters of water are removed from the drainage system that is a saving of approx €4000 euros. If 250 houses out of 515 implemented 1000 liter water butts and 400 liter rain water planters the reduction in water going to the drainage system would be approx 350000 liters per rain event and the reduction in water processing costs would be approx €900 euros per rain events and if 10 rain events occured in a year an overall saving of approx €9000 euros. Thus I believe Uisce Eireann would see the benefits of providing some capital funding for this tpe of project over a multi year period. 

Costs to the home owners in our area 

• Free to OAP's in our area that our members of the residents association

• Significant reduction in overall retail cost of this type of solution for younger house holders if some level of funding can be achieved 

Overall outcome of the proposed initiative 

• A 75% uptake by the 600 households within our area 

• A reduction of over 500k liters of rain water per rain event reaching the main drainage system  in our area and a total of approx 5 million liters of water going to main drainage system over a 1 year period, saving Uisce Eireann over €10K per year in water processing costs and help to reduce the overall reqrement for a capital intensive program to upgrade the drainage  system in our area

• The solution provided free to all OAP's in our area and the solution is provided to other house holders in our area well below retail cost

Note: this would all be predicated on funding that can be achieved (multiple sources and initiatives) and volume discounts from manufacturer based on how many house holds would be interested in the initiative. e.g if 250 house holds signed up and 50 were OAP's I believe with funding and discounts achieved etc

The bottom line 

• Rainwater events are getting larger and the drainage system is showing signs within the estate that it cannot fully cope with large rainwater events which could lead to flooding events that could effect householders within the estate depending on your location in the estate