They proposed five strategies - forest protection, reforestation, agricultural best-management practices, riparian restoration and forest-fuel reduction - each of which would be adapted to local circumstances. They found that increasing the rate of adoption of best-management practices on 0.2% of watershed agricultural areas from which water is sourced in the 100 largest cities would result in a 10% sediment reduction in the water supply (constituting the most cost-effective option, as shown in Figure 4.3). The same option is less cost-effective than others w'hen it comes to nutrient reduction (also Figure 4.3).