Hydrology & Water Resources: Rainfall, Runoff & Reservoirs

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Turn five rain-gauge readings into one catchment rainfall, first as a plain average, then with Thiessen polygon weights, and convert it into a water volume.
• Size the design flood of a small urban catchment: a composite runoff coefficient, the Kirpich time of concentration, the intensity from an IDF curve and the peak flow in m³/s.
• Build a composite curve number, the retention S and initial abstraction Ia, then compute runoff depth and volume for six storms with the SCS-CN equation.
• Convolve a 3-hour excess-rain hyetograph with a 1-hour unit hydrograph in a step table, add baseflow and check the mass balance of the runoff volume.
• Run a monthly water balance for the Fernbrook Reservoir in a dry year: evaporation volumes, end-of-month storage, months below the minimum operating level and a storage chart.
• Rank three years of monthly flows, compute the exceedance probability of each, plot the flow duration curve and read the Q95 low flow.
• Project the town's population to 2046, turn it into daily demand, add non-revenue water and a peak-day factor, and find the year the treatment plant runs out of capacity.
• Compare five pipe diameters for a new 1.8 km main: cross-section area, flow velocity, Hazen-Williams friction loss, and the smallest pipe that meets the head-loss limit.