The Environment Southland (ES) report showed 856 cases of speeding were logged for the period from April-June where drivers exceeded the limit by over 10kmh.
For that same period, there were a total of 28 times where the speed limit was exceeded by more than 20kmh.
ES made the data public in a report which noted further analysis of driving behaviour had been requested by the risk and assurance committee.
"As requested by the health and safety committee, over-speed reports have been distributed to the divisional managers for their team speeding 15kmh or more," the report read.
It noted there had been a "significant decrease" in speeding in the medium and high categories since managers began receiving those monthly reports.
All ES vehicles were fitted with an in-vehicle monitoring system, which included an audible alarm which went off when the speed limit was exceeded.
When this occurred, an "event" was logged in the system.
In response to questions from Local Democracy Reporting, ES health, safety and risk manager Paul le Roux said the highest speed recorded in the period from April to June was 126kmh.
The vehicle exceeded the 100kmh mark for an eight-second period, which was consistent with an overtaking manoeuvre, he said.
During the same quarter, two drivers drove for 2.6km at speeds 20kmh over the speed limit.
"Where speeding is considered an issue, there is a conversation, in the first instance, with the driver regarding health and safety," Mr le Roux said.
Environment Southland staff travelled almost 190,000km in fleet vehicles between April and June.
Speeding was being discussed at all levels of the organisation and remained a focus at committee level, the council report said.
■LDR is local body journalism co-funded by RNZ and NZ On Air.