Voluntary data submission allows for a change in the makeup of the dataset year over year and can complicate annual trending. Beginning with the 2021 DIRT report, CGA utilized a consistent dataset compiled specifically for three-year trending which is referred to as the comparable dataset. The dataset includes a balanced representation of stakeholder data from companies that entered reports for all three years (2019, 2020 and 2021). The dataset includes a representative sample of reporting stakeholders matching the typical distribution of reporting stakeholders in a given year and includes data from facility owners/operators, 811 centers, locators, excavators,[1] public and private water, and regulatory agencies.
Table 3—Comparable Dataset Totals
Year
|
Total Reports
|
Unique Reports
|
Data Quality Index (DQI)
|
2019
|
170,298
|
157,003
|
65.5
|
2020
|
174,975
|
163,052
|
66.5
|
2021
|
198,676
|
176,317
|
67.6
|
The unique reports numbers are used in the Trend Analysis 2019-2021 figures and tables in this section of the report.
CGA’s statistical consultant, Green Analytics, used the comparable dataset to analyze high-level damage trends in the U.S. from 2019 to 2021. The objective of this year’s statistical analysis was to evaluate how damage counts in the United States are changing over recent years after accounting for important factors driving damages.
The statistical analysis largely indicates that damage counts have remained consistent over the 2019 to 2021 period. However, there is some evidence from one of the statistical models to suggest that damages in 2021 were higher than those in 2019 and 2020, although this finding is statistically significant at a lower level of confidence. This detailed analysis is summarized in Appendix B and provides more detail on the inputs and variables used by Green Analytics.
Overall, the data suggests that damage counts have remained steady from 2019 through 2021, with the possibility of an increase in counts for 2021 relative to previous years. Table 3 shows an increasing number of damages each year for the comparable dataset. However, Green Analytics’ analysis accounted for factors that influence damage counts, such as construction spending and activity, changes in state population, 811 center transmissions, etc. With the factors considered, damage counts are, at best, holding steady. Furthermore, damage counts have been proven to correlate with infrastructure spending. Based on historical trends, as infrastructure spending increases in the coming year(s), stakeholders would likely see a proportional increase in damages, all else being equal.
[1] The 811 centers (one call centers) also entered reports with excavators as the event source.