Water Consumption Research Project Phase 2 Methodology circa 4 - PowerPoint PPT Presentation

Water Consumption Research Project Phase 2

Methodology • circa 4 months meter readings from 7,439 households – Four counties: Dublin, Kildare, Meath and Wexford – Covers period December 2013 to May 2014 – Different architecture types • Consumption per day calculated as total metered quantity divided by number of days from date of install to date of meter read.

Methodology • Focus of WCRP Phase 2 is to gather data to study consumption in households with children • Door to door survey carried out by market research company • Sensitive sites removed from list • Data collected: – Architecture type – Number of bedrooms – Number of occupants per house, including adults and children • Assumption that surveys are answered and recorded honestly and in good faith

Limitations • No data on socio-economic profile or age of respondents • Sample selection limited to households that had meters installed between December 2013 and January 2014 • Survey limited to 4 counties in Leinster • Bias towards suburban areas and associated demographics and architecture types • No apartments in this phase of the WCRP

Assumptions • Households greater than 800 litres/day removed from analysis on the basis of proposed first fix policy 1 • Household usage is most closely correlated with occupancy • Children are defined as children under 18 living in the household. • Sample is not representative of CSO population census but provides a useful snapshot of households metered so far • Annual consumption is extrapolated from available data • Proposed household allowance is 30m 3 per year 1 A total of 63 outliers were removed. This includes one household removed as it had no adult occupants.

Survey sample (ex outliers) Children 0 1 2 3 4 5 6 7 Total 1 107 58 20 17 9 2 1 2 827 179 169 285 144 35 10 4 1 Adults 3 156 72 40 28 13 2 1 4 45 31 12 2 5 7 3 2 1 1 6 2 1 1 Total 343 244 334 167 39 12 4 1 1,144

Results (litres per person per day) Children 0 1 2 3 4 5 6 7 1 176 148 96 103 94 126 - - 2 141 102 91 78 81 82 68 40 Adults 3 104 86 81 82 73 79 - - 4 102 80 109 - - - - - 5 101 78 77 54 - - - - 6 - 70 92 - - - - -

Comparison to Phase 1 Phase 1 Phase 2 Sample size litres/person Sample size litres/person 1 occupant 94 171 58 176 2 occupants 335 140 199 142 3 occupants 353 108 258 102 4 occupants 428 94 365 92 5 occupants 265 83 189 79 6 + occupants 111 84 75 81 Total 1,586 1,144 Apartment 33 162 - - Detached 435 110 178 101 Semi-detached 748 106 498 103 Terraced 370 109 468 106 Total 1,586 1,144

Survey sample (ex outliers) Children 0 1 2 3 4 5 6 7 Total 1 107 58 20 17 9 2 1 2 827 179 169 285 144 35 10 4 1 Adults 3 156 72 40 28 13 2 1 4 45 31 12 2 5 7 3 2 1 1 6 2 1 1 Total 343 244 334 167 39 12 4 1 1,144

Two adult households 160 140 m3 per household per year 120 100 80 60 40 20 0 1 adult 2 adults 2 adults, 1 child 2 adults, 2 2 adults, 3 children children Incremental consumption

Scatterplot – Phase 1 400 y = 20.181x + 56.493 350 300 m3 per household per year 250 200 150 100 50 0 0 1 2 3 4 5 6 Occupants

Scatterplot – Phase 2 400 y = 18.453x + 58.725 350 300 m 3 per household per year 250 200 150 100 50 0 0 1 2 3 4 5 6 7 8 9 10 Occupants

Billable quantity – 38m 3 per child 180 160 140 Billable quantity (m 3 per year) 120 100 No Children 80 Children 60 40 20 0 1 2 3 4 5 6 7 8 Occupants

Billable quantity – 20m 3 per child 180 160 140 Billable quantity (m 3 per year) 120 100 No Children 80 Children 60 40 20 0 1 2 3 4 5 6 7 8 Occupants

Average bill index* @ 38m 3 per child Children 0 1 2 3 4 5 6 7 1 100 140 60 69 8 161 - - 2 207 136 100 55 61 60 36 0 Adults 3 239 176 154 151 73 32 - - 4 338 230 374 - - - - - 5 439 293 260 35 - - - - 6 - 316 465 - - - - - * 2 adults, 2 children = 100

Average bill index* @ 20m 3 per child Children 0 1 2 3 4 5 6 7 1 55 97 67 103 95 227 - - 2 113 99 100 86 107 124 75 0 Adults 3 130 120 128 145 119 157 - - 4 184 150 259 - - - - - 5 239 187 197 102 - - - - 6 - 200 309 - - - - - * 2 adults, 2 children = 100

Billing distribution 300 @ 20m 3 increases the 250 billable quantity by 41% Indicative m 3 per year 200 150 100 50 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percentile Billable quantity @ 38m3 Billable quantity @ 20m3

Effective volumetric rates 100% @ 20m 3 increase in 90% households paying a bill 80% Percentage of volumetirc tariff from 75 to 90% 70% 60% 50% + 15 % 40% 30% 20% 10% 0% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Households percentile Effective Rate @ 38m3 Effective Rate @ 20m3

Results @ 38m 3 per child • Households with children pay less than households without children • In total, 25% of households do not receive a bill – 34% of households with children do not receive a bill versus 4% of households that do not have children • 61% of water consumed is non-billable • Effective volumetric rate, on average, is 34% of the actual volumetric rate

Results @ 20m 3 per child • Households with children pay less than households without children • In total, 10% of households do not receive a bill – 12% of households with children do not receive a bill versus 4% of households that do not have children • 45% of water consumed is non-billable • Effective volumetric rate, on average, is 47% of the actual volumetric rate