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You are the engineer assigned to the design of this subdivision. Assuming your audience is the HCC engineers and planners, write a design report focusing on two main parts:

1. How you propose to approach the stormwater management of this subdivision using the ARC Low Impact Design Approach (TP 124, Chapters 3 & 4). This will be an overview of the proposed approach, no calculation or detailed design required.

Sub-tasks:

· Identify potential impacts of the proposed development and discuss the need to apply the 5 LID principles of TP124;

· Identify specific site resources and the benefits they may provide;

· Discuss prevention and mitigation measures you may use.

2. Your planning and design of a stormwater management system for your subdivision. You may use guidelines from the Christchurch City Council WWDG Chapter 6 (supported by Chapter 20 & 21), or the equivalent Auckland City Council Documents (TP10 & TP108), or relevant local and regional council documents. However, ‘area specific’ hydrology information like rainfall data etc. will have to be obtained from local district standards.

Sub-Tasks:

· Divide your subdivision into sub-catchments and assign stormwater management systems (treatment trains) for each sub-catchment utilising the existing natural resources.

· Show the sub catchments and location of proposed stormwater systems on a drawing include natural features (i.e. could use an aerial photo).

· Provide sizing calculations for at least ONE first flush interceptor*, plus ONE soakage system* OR ONE detention basin** you propose. This will have to include runoff calculations for the design storm stipulated by the document used or local government of your site (you choose by research and please state why you have chosen this AEP). Design requirements should be stated and referenced.

· Plus, then calculate the urban pollutant export per year from your subdivision, for this particular calculation assume it is 2 years old, fully developed and construction complete.

· Provide layout sketches, typical (or examples found elsewhere) drawings and photos of proposed design structures.