Table 4 Magnitude frequency relationships for SMD based on 11 years weighing lysimeter data at CHRS End of April SMD = -39.818y – 16.085 May SMD = -19.586y + 20.068 June SMD = -29.364y + 36.068 July SMD = -30.433y + 51.054 August SMD = -16.706y + 39.180 September SMD = -16.926y + 0.180 Where y = modified reduced variate = [(-ln ln (1- 1/T) – 3.3842) * 1.09348 * T-0.046518] + 3.3842. Where T = return period (years).