The Stormwater and Flood Implications - Engineering Assignment Help

Assignment Task

Task

You are working as the Stormwater Drainage and Flood Manager in the Large Council. As part of your role, you have been asked to assess the stormwater and flood implications of a proposed urban development beside the Big River. This development will be located upstream of an existing urban development. Upstream of the development is farmland. Within the development, a bridge over the Big River is proposed.

For the purposes of assessing developments of this type, Council has approved the following criteria:

Allowable upstream afflux for the 1 in 100-year AEP design flood levels.

1. Upstream urban areas - 25mm
2. Upstream rural areas - 250mm

Allowable flows from the development.

1. No increase in 1 in 100-year AEP flow
2. 10% change in the volume of runoff over a water year
3. No erosion of the riverbed (this requires minimal, if any, increase in cross-section average velocities).

Additional data about the catchment is.

• The catchment is located on the north coast of NSW. Hence the river and its tributaries draining this catchment flow from the west to east of the catchment.
• Catchment area is 8,000km2.
• There are two tributaries

1. The major tributary drains 6,500km2.
2. The minor tributary drains the remaining 1,500km2 of the catchment.

Catchment drainage characteristics.

1. Both tributaries draining the catchment have 1,500km2 of headwater region where the catchment is hydraulically steep with fast-flowing drainage networks.
2. The remaining 5,000km2 consists of channels and floodplains where the rivers would be considered hydraulically mild.

• Three rain gauges monitor rainfall in the catchment.

• One gauge is located in the upper headwaters of the catchment and has a daily record of 61 years.
• The other two rain gauges are located on the floodplains near the mouth of the river. One of the downstream gauges has a daily record of 110 years while the other has a continuous digital record of 25 years.
   

Two stream gauges are available in the catchment.

• One stream gauge is located in the headwaters of the catchment at the site of a dam. The record length available from this stream gauge is 55 years with 25 years of this record impacted by the construction of a dam.
• The second stream gauge is located near the mouth of the river and has a record length of 20 years. The total period of this record is post-dam construction.
• In addition to the gauge record, local newspapers highlight the largest flood since western settlement of the region occurred 93 years ago.
• Detailed LIDAR is available for the catchment. This LIDAR has been assessed as having a vertical accuracy of 100mm.

In your role, you have been tasked with determining the studies that need to be undertaken. These studies will entail both data analysis and catchment modelling.

A) Explain the principles and assumptions necessary for the data analysis. In preparing this explanation, consider what questions (and how this will assist in the determination of the development approval) will be addressed through this data analysis. Also, consider how the construction of the dam will impact on this data analysis and recommend an approach to mitigate this impact.

B) Explain the principles and assumptions necessary for the catchment modelling. In preparing this explanation, consider what questions (and how this will assist in the determination of the development approval) will be addressed through this catchment modelling. Include in your discussion, how you would use the available data to ensure the catchment model is valid.

C) Discuss whether the catchment model used to consider flood issues should be used also for consideration of the stormwater drainage in the proposed development, or vice versa.

D) The assessment of potential erosion at the site of the proposed bridge requires minimal change in cross-section averaged velocity. Discuss how you would determine any potential velocity changes. In this discussion, ensure you highlight the hydraulic principles behind your recommendation. Also, include in your discussion what data you need to ensure the validity of any proposed model.

This Engineering Assignment has been solved by our Engineering Expert at Exam Question Bank. Our Assignment Writing Experts are efficient to provide a fresh solution to this question. We are serving more than 10000+ Students in Australia, UK & US by helping them to score HD in their academics. Our Experts are well trained to follow all marking rubrics & referencing Style. Be it a used or new solution, the quality of the work submitted by our assignment experts remains unhampered. You may continue to expect the same or even better quality with the used and new assignment solution files respectively. There’s one thing to be noticed that you could choose one between the two and acquire an HD either way. You could choose a new assignment solution file to get yourself an exclusive, plagiarism (with free Turn tin file), expert quality assignment or order an old solution file that was considered worthy of the highest distinction.