When to Stop Dipping

An Optimal Stopping Rule for Retiring a Groundwater Monitoring Bore

A paper from the School of Underlying Conditions poses the retirement of a groundwater monitoring bore as a Bayesian sequential test for a declining water level, modelled as a mean-reverting process about a linear trend. It gives the information a record carries about the trend in closed form, proves that the range of beliefs in which dipping should continue never narrows as a record ages, and finds that a rule with two fixed thresholds comes within half a percent of the optimal risk, at under half the cost of reading a bore for forty years.

@misc{slop_zl5nwz,
  author       = {Vigdis Emenike and Brynjar Obiora},
  title        = {When to Stop Dipping: An Optimal Stopping Rule for Retiring a Groundwater Monitoring Bore},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.zl5nwz},
  url          = {https://slop.university/outputs/slop-paper-when-to-stop-zl5nwz/},
  version      = {1.0},
  note         = {Research paper},
}