Transmission Line Distance Data FAQ
What does distance to transmission line represent?
Distance to transmission line is calculated for each parcel and represents the distance (in meters) that the parcel lies from the nearest ‘relatively high voltage’ (‘relatively high voltage’ = 69kv - 765kv) electric transmission line as reflected in the dataset maintained by the Homeland Infrastructure Foundation-Level Data (HIFLD) for transmission lines More on that transmission line dataset can be found in HIFLD
What is the source of the distance to transmission line Data?
Esri utilized the combination of the Regrid parcel data and the HIFLD transmission line data to calculate the distance from each parcel to the nearest relatively high voltage electric transmission
Is the distance to transmission line specific to each parcel?
Yes, the distance to calculation is specific to each parcel
What is the methodology to calculate the distance to transmission line?
The distance to transmission line is calculated by assessing the entire polygon geometry of each parcel and calculating the distance to every transmission line within 100 miles of the parcel.The smallest distance value for each parcel/ll_uuid is then assigned as this value. Distances are calculated using a planar distance method (in meters) after projecting both parcels and transmission lines to an appropriate equidistant coordinate system
When is the distance to transmission Line data updated?
Regrid does not control the HIFLD data but it appears this data will be updated on an annual basis, likely in the first quarter of each year. Regrid is working with Esri still working with Esri to determine at what cadence this process will be re-run to incorporate new parcels and the necessary recalculation of adjusted parcels