Table 6 Estimated cost of a city-wide RB system (r1–r5), value of harvested rainwater, cost and area of a city-wide RG system (r6–r11).
Row | Parameter | Value | Source/formula |
|---|---|---|---|
r1 | Harvested rainwater during the 4-year representative wet period (m3) | 1,014,490 | Modeling output |
r2 | Harvested rainwater over the 50-year expected life of RB units (m3) | 12,681,124 | r1 × 50/4 |
r3 | Estimated cost of one cubic meter of tap water in San Diego ($) | 5 | Statistica62 |
r4 | Estimated Value of harvested rainwater over the 50-year expected life of RB units ($) | 63,405,618 | r3 × r2 |
r5 | Estimated cost of RB implementation in the city ($) | 3,315,358 | Equation (2) |
r1 | Total area of urbanized region (m2) | 5,784,944 | GIS mapping |
r6 | Total area of urban parcels (m2) | 4,120,476 | GIS mapping |
r7 | Ratio of RG surface area to catchment area (or urban parcels) | 0.05 | Liu and Fassman-Beck56 |
r8 | Total area of the city-wide RG system (m2) | 137,273 | r2, r3, and adoption rates |
r9 | Estimated cost of one square foot (or 0.093 m2) of RG ($) | 10 | CostHelper57 |
r10 | Ratio of RG surface area to urbanized area (%) | 2.4 | r4/r1 |
r11 | Estimated cost of the city-wide RG system ($) | 14,776,000 | r5 × r4/0.093 |
