If you want to model the effects of various demand-side management (DSM) strategies for reducing demand, you can use either a disaggregated or aggregated approach. The disaggregate approach would make changes to the water use rates on individual branches. For example, to model a program to promote efficient washing machines, you would either decrease the water use rate for washing machines (if there was only one branch for washing machines), or increase the share of efficient washing machines (if there were two branches--one for traditional washing machines and one for more efficient ones). Another example would be a tiered pricing strategy that charged more per unit water for higher usage rates, thus encouraging individuals to reduce their consumption. The benefits generated by this pricing strategy could be modeled using the BlockRate function. However, you would need to separately estimate the reduction in activity level or water use rate due to increased prices.
The disaggregated approach works well if your demand data is already disaggregated to the level of end-uses or devices. However, most demand analyses will not be so disaggregated. With the aggregated approach for DSM, you estimate the fraction of total demand for a demand site that could be reduced by DSM programs, and enter that fraction under DSM Savings. For example, if efficient washing machines and toilets consume 60% less water than traditional ones, and those end uses account for 4% of overall water consumption for a demand site, enter 2.4% for the DSM Savings.
If there are costs associated with these DSM programs, enter the cost per unit of water saved on the DSM Cost tab.
Entered on: Data View, Branch: Demand Sites, Category: Demand Management, Tabs: DSM Savings, DSM Cost