In the Holocene, deltas and coastal plains developed due to relative sea level rise (RSLR). Past coastal and inland water levels are preserved in geological indicators, like basal peats. We present a dataset of 712 Holocene water level indicators from the Dutch coastal plain, relevant for studying RSLR and regional subsidence, compiled in HOLSEA workbook format. Our new, internally consistent, expanded documentation encourages multiple data uses and to report RSLR uncertainties transparently.