Return period Exceedence probability Predicted water level, zp (m) Associated design risk (T) Q(z) 1920s Today 2050: +30 cm 2100: + 1m 2100: +1.5m 2100: + 2m 50 yr 100 yr 500 yr 2 50.0% 5.204 5.263 5.597 6.294 6.803 6.844 1.000 1.000 1.000 5 20.0% 5.327 5.388 5.727 6.432 6.881 7.191 1.000 1.000 1.000 10 10.0% 5.391 5.453 5.796 6.505 6.938 7.330 0.995 1.000 1.000 25 4.0% 5.459 5.523 5.868 6.585 7.021 7.405 0.870 0.983 1.000 50 2.0% 5.503 5.567 5.915 6.636 7.066 7.488 0.636 0.867 1.000 100 1.0% 5.543 5.608 5.957 6.683 7.112 7.543 0.395 0.634 0.993 200 0.5% 5.579 5.644 5.995 6.727 7.155 7.593 0.222 0.394 0.918 500 0.2% 5.622 5.689 6.041 6.779 7.212 7.639 0.095 0.181 0.632 Assuming you want a new building to have a 100 year lifetime, what is the design risk associated with a >4 m flood