On October 12, 2022, the CMAP Board approved an update to the ON TO 2050 long-range plan, including an updated indicators appendix. This indicator measures the total number of acres of impervious surfaces in the region; it is the entire amount of hard surface (such as buildings, sidewalks and streets) in the landscape. Imperviousness is an important environmental indicator because it is negatively associated with various measures of the biological health and physical integrity of surface waters. Targets CMAP’s regional socioeconomic forecast projects that households and jobs will each grow by approximately 16 percent over 2010 levels by 2025, and by approximately 36 percent over 2010 levels by 2050. The target methodology assumes that growth in impervious cover will slow from the current rate as the region’s population and employment density increase through infill and reinvestment. The 2025 target for impervious acreage represents growth rate in impervious cover from 2010 equal to 60 percent of the rate of household and job growth over the same period (i.e., a 10 percent increase in acreage over 2010). The 2050 target represents growth in impervious cover from 2010 equal to 50 percent of the rate of household and job growth over the same period (i.e., an 18 percent increase in acreage over 2010). While the targets show growth in total impervious acreage, they represent a continual (and accelerating) decline in the region’s impervious area on a per-household, per-capita, and per-job basis. 2025: 605,000 acres or less of impervious area 2050: 650,000 acres or less of impervious area Indicator Acres of impervious area Key Actual Target Source CMAP analysis of data from the United States Geological Survey National Land Cover Database. See Indicators Appendix for methodology The following chart shows how the impervious acreage targets translate to a per-household rate, based on forecasted numbers of households from the ON TO 2050 socioeconomic forecast. While growth in impervious acreage has recently outpaced growth in households, the targets would reflect a reversal of this trend. Indicator Impervious acres per household (actual and forecasted, based on targets) Key Actual Target Source CMAP analysis of data from the United States Geological Survey National Land Cover Database. See Indicators Appendix for methodology GO TO 2040 context This indicator has been carried forward from the GO TO 2040 plan update. However, there has been no new data released since the plan update was written, so no evaluation can be made of implementation progress at this time. The plan update set 2020 and 2040 targets of 590,000 and 640,000 acres of impervious area, respectively, which are largely in line with the ON TO 2050 targets. Sections TargetsGO TO 2040 context ON TO 2050 plan Download the executive summaryOpen Download the executive summary in a new tab Download the full reportOpen Download the full report in a new tab CMAP Update Newsletter sign-up Opens in a modal Related recommendations Click to read Protect and enhance the integrity of aquatic systems Environment