Designing of Stormwater Drainage In Practical Project 1, you and your group members performed a closed loop level run to determine the Australian Height Datum (AHD) Reduced Level (RL) of approximately 10 ground points along the centreline of a pipe. An example “SAMPLE LEVEL SHEET” is provided as reference. Based on observations collected, your task is to design a draining pipe connecting the given mark (i.e. “A” representing the proposed location of the pump station) to the mark you placed at the edge of the concrete of the athletics track (“B” representing the proposed location of the pipe terminus.). The proposed pipeline has the following design requirements. An example “SAMPLE PLAN – PROPOSED PIPE DRAIN AT YARRA BEND” is provided as reference.

• Plotted neatly on an A4 performa sheet supplied. • Has appropriate horizontal and vertical scales. For example, 1:500 (horizontal scale) and

1:100 (vertical scale). • The start point of the pipeline is “A”, the pump station. The end point “B” is the pipe terminus. • RLs of the pipeline chainage and existing surfaces are to be obtained from the level sheet. • At the chosen vertical scale (e.g., 1:100, again just as example), the existing surface levels

are plotted. These points are then joined to join a profile of the existing surface. • The proposed pipe has specific diameter requirement, which is 0.5 m, and is to be plotted.

Assume pipe thickness as zero (0.00m). • The pipeline design needs to be a minimum cover of 0.50m (i.e., minimum depth to invert

of 1.00m) and a maximum cover of 3.00m (i.e., maximum depth to invert of 3.50). Note: In the sample provided (see “SAMPLE PLAN”), the minimum cover occurs at chainages 15m and 84.3m giving invert levels of 56.63m and 51.31m, respectively. Note that it may be necessary to introduce a change in grade for the proposed pipe in order to fit the above criteria.

• The gradient of the pipe (as ratio and %) is then computed.

• By proportion (similar triangles), the invert levels are then computed for all other chainages. • The gradient is to be also quoted as % grade, i.e., 7.67%. • Finally the “depth to invert” is computed. Depth to Invert = Existing Surface – Invert Level. • Longitudinal plan is to show chainage, RL of natural surface, RL of pipe invert, depth to pipe

invert (i.e. RL natural surface – RL pipe invert). • The plan should include natural surface RLs, invert level, depth to invert and chainage and

annotations, appropriate vertical and horizontal scales, gradient of the pipe as a percentage (%) and ratio grade.