Rainwater Harvesting System Analysis

This assignment examines the financial viability and environmental benefits of a 75,000-liter (75kL) rainwater harvesting tank system. It uses life-cycle costing analysis to compare the initial investment cost with long-term savings on water bills and reduced strain on municipal drainage systems. The study emphasizes the potential for sustainable urban water management by utilizing rainwater for building needs and minimizing runoff.

Tanks 1
RAINWATER TANKS
Tutor’s Name
Institution’s name
City
Date

Tanks 2
Table of Contents
1. Executive Summary.............................................................................................................................3
2. Objectives............................................................................................................................................3
3. Specific Objective................................................................................................................................3
4. Introduction.........................................................................................................................................3
5. Water Sensitivity of rainwater tanks in Urban Designs........................................................................4
6. Water Sensitive Urban Community Project Initial Findings.................................................................5
7. Conclusion...........................................................................................................................................6
8. References...........................................................................................................................................7

Tanks 3
1. Executive Summary
The examination of the 75kL tank in the various scenarios of beneficiaries of fictitious multi-story set up
led to the development of model tank using rainwater from analyzed development that matches the
required water savings. Such findings made it possible to conclude that is it possible to make an
achievement of payback system that harvests rainwater under appropriate conditional and scenarios.
The cost of maintenance and capital came from the overall life-cycle of the model whereas the plumbing
cost majorly existed in the capital cost and related to the pump replacement and maintenance
expenditure. Various assumptions were made in such a development that included; tank size, discount
rates, and lot size.
2. Objectives
This project tries to come up with the cost-minimized potential strategies that may solve the existing
obstacles to the wide adoption of Water Sensitive Urban Design for the purpose of managing the water
resources in the urban region presenting and discussing the issue in these tank designs and produces the
sustainable design.
3. Specific Objective
In the practice of utilizing urban stormwater, the following key objectives come to play; minimization of
development cost, protection of natural systems in urban areas, integration of treatment of stormwater
into existing landscape, protection of water quality and reduction of peak flows and run-off.
4. Introduction
The wide water supply introduction in the Australian system meant that there would be a need for local
storage, collection, and reuse of the rainwater that had a reduction the 20TH century. The harvesting of
rainwater with the use of rainwater tanks is an emerging solution important for its renewability and
alternative supply of water in Australia. The use of the tank is known for the technique that reduces the

Tanks 4
reliance on the potable water supply mains. Using rainwater tanks also reduces the runoff of
stormwater in the urban system. Although rainwater is a source of significant water volume to individual
households by the supply of good non-potable purposes, there is yet an establishment of the subsidy
levels together with the water prices. There also is a general misunderstanding on the long-term viability
in finance viability of the tanks mostly in the multi-story resident development. The paper focuses on
such residential developments. This paper, therefore, makes an investigation of the lifecycle analysis is
on the 75kL tank. The Excel-based model of the hypothetical tank was produced to make a 60-year
rainfall data analysis determining the water saving potential.
5. Water Sensitivity of rainwater tanks in Urban
Designs.
Urban settings have reduced previous areas that lead to increased runoff volume, pollution, and flow
velocity wash off and build up. The demand for water in the urban areas is normally solved by the
importing treated water over long distances with considerable cost. Therefore the engineers have come
up with the water sensitive urban design whose principal objectives is to produce a cycle management
that can minimize urbanization impact on the natural water resources and waterways. The tank is
important for its uses in collecting and re-using the runoff from stormwater making it advantageous in
savings and runoff volume reduction.
(Ladson, 2008) Produced an assessment of the life cycle in assessing the rainwater tanks of a 600l
together with a 2250l capacity tank with an estimation of economic benefits with the tank cost from the
perspective of consumers. The household savings produced an estimation billing of about 29.6% for a
2250l tan. There was the discovery that neither the tanks had the possibility of paying back water price
for the used 30 years. (Barnett, 2016)Produced a demonstration of the particular mix of the control
techniques in the source in making use of the tanks for economic benefits. (Ali & Ward, 2014)Had an
investigation into the traditionally based scenario for the application in the urban cycling of water

Tanks 5
together with alternatives that included the use of rainwater tanks. There was a discovery of the
benefits of search tanks that used cycled rainwater. Low rates in the interest meant an implementation
of the cycle rainwater tanks usage would lead to delayed of supply water sites for about 34 years.
6. Water Sensitive Urban Community Project Initial
Findings
(Lehmann, 2010)Produced use computer modeling tool that developed the harvesting system of
rainwater. There was an argument that the existing methods lead to an overestimation of the efficiency
in the hydraulics together with the saving cost. (Brears, 2016)Produced an investigation on the viable
economy and the reduction in mains water efficiency in the multi-story housing residential. The
consideration was on a 70 occupant building that used it for 4 stages that included laundry, toilet
flushing, outdoor use and hot water. Such consumption produced 0.036kL/person/day in toilet flushing,
10kL/person/year in outdoor usage. More result was that 10kL tanks had 10% total demand and 100kL
tanks having 50% demand thereby making larger tanks more reliable.
(Younos & Parece, 2016)Made a presentation of the cost of the life-cycle from the analysis of the 75kL
tank of rainwater in the Sydney city. The analysis of such tank financially provided a better realization of
the tank cost result produce of a 60-year life-cycle using the current water supply mains price together
with the existing interest regime. The ratio benefit of coast estimation was found to be in the range 64%
- 654% using the various rates of interests and the less-conservative and conservative cost estimates.
There was a note of the lower rates of interest and the increased price of water that may have made the
rainwater tanks become better financially viable whereas the increased rates of interest led to less
favorable results.
Life-Cycle Costing

Tanks 6
This is the assessment of product cost over the life-cycle or the portion, therefore (Sharma, et al., 2015)
or it could mean the acquisition sum of cost together with the cost in ownership of the life cycle of a
product (Debo & Reese, 2002). Such a study uses the nominal cost concept together with the nominal
rate in discount. The conversion of the nominal cost (CN) to the stipulated discounted cost (CP) is done as
below;
(Brears, 2016)
In here, dn represents the per annum rate nominal discount whereas y represents a required number of
years.
Method.
A simulated performance of 75kL tank was used in rainwater tank water balance model for a period of
60yrs with the life cycle in harvesting rainwater being undertaken. The adoption of the 75kL size of the
tank was due to the similarity in the study that made it appropriate for multi-story application in
buildings (Ali & Ward, 2014). The paper composed of hypothetical development of the rainwater tank
cost and use. The assessment of such rainwater tank system came from example development of the
tank’s life cycle cost.
7. Conclusion
To develop a sustainable city that uses water economically and efficiently, the development of a 75kL
tank that harvests rainwater is proposed by this paper as the way forward. The buildings in the city
would get clean water as well as reduce the surface run-off. An improvement would, therefore, be
noticed in the drainage system thereby developing a sustainable ecological environment.

Tanks 7
8. References
Ali, F. & Ward, S., 2014. Alternative Water Supply Systems. 1 ed. Hobart: IWA Publishing.
Barnett, C., 2016. Rain: A Natural and Cultural History. reprinted. Port Macquarie: Crown Publishers.
Brears, C., 2016. Urban Water Security. illustrated ed. Mackay: John Wiley & Sons.
Debo, T. & Reese, A., 2002. Municipal Stormwater Management, Second Edition. 2, illustrated, revised
ed. Hervey Bay: CRC Press.
Ladson, A., 2008. Hydrology: An Australian Introduction. illustrated, reprint ed. Tamworth: Oxford
University Press.
Lehmann, S., 2010. The Principles of Green Urbanism: Transforming the City for Sustainability. illustrated
ed. Melbourne: Earthscan.
Sharma, A., Begbie, D. & Gardner, T., 2015. Rainwater Tank Systems for Urban Water Supply. illustrated
ed. Rockhampton: IWA Publishing.
Younos, T. & Parece, T., 2016. Sustainable Water Management in Urban Environments. illustrated ed.
Rockhampton: Springer.