| Regimental number | 358 |
| Place of birth | Tiaro Queensland |
| Religion | Presbyterian |
| Occupation | Labourer |
| Address | Brisbane, Queensland |
| Marital status | Single |
| Age at embarkation | 18 |
| Next of kin | Father, George Thomas Groundwater, Cheviot Hills, Tiaro, Queensland |
| Enlistment date | |
| Rank on enlistment | Private |
| Unit name | 42nd Battalion, B Company |
| AWM Embarkation Roll number | 23/59/1 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A30 Borda on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 15th Battalion |
| Fate | Returned to Australia |
| Family/military connections | Brother: 359 Pte John Robert Sinclair GROUNDWATER, 42nd Bn, returned to Australia, 1 November 1917. |
| Other details |
War service: Western Front Medals: British War Medal, Victory Medal |
| Date of death | |
| Place of burial | Tiaro Cemetery |