Projects Dealing with Flooding and Erosion - Assignment Example

Project Evaluation Name: Lecturer: Course: Date: Introduction Engineering projects that deal with the challenges of flooding and erosion are significant. In the past severe flooding incidences have been witnessed in various regions , which calls for the need of effective projects that are able to alleviate such problems. This paper seeks to examine the effectiveness of various projects in dealing with flooding and erosion. The scope of the analysis will also be grounded on providing suggestions for improvement on one of the projects. The Pevensey Sea Defence Scheme The Pevensey Bay Sea Defence scheme can be described as a unique project based on the fact that it is the first project that involves Public Private Partnership. It can be stated that the partnership between the Environment Agency and Pevensey Coastal Defence Ltd is an effective approach of dealing with the problem of erosion and flooding from the sea (PCDL, 2014). The effectiveness of the project is influenced by the capability of the shingle approach in dealing with the risk of flooding and erosion. The project comprises of a naturally developed shingle bank that stretches 9km between Bexhill in East Sussex and Eastbourne. The shingle is supported by a timber groyne field, as illustrated in (figure 1). The approach adopted by the project is to ensure that the shingle is managed in an adaptive manner for a period of 25 years. In the previous years, the timber groyne existed however, no proper management existed, and therefore the method seemed ineffective. For instance, in the late 1990s, the timber groyne would reach the end of their useful life and thus posing a great risk ( PCDL, 2014).The Pevensey Sea Defence Scheme, therefore intends to ensure that the timber groyne still maintain their usefulness, an aspect that makes the shingle approach effective in dealing with the risk of flooding and erosion. Figure 1. Pevensey Sea Defence Scheme - Timber Groynes When evaluating other projects for instance Rossall Sea defences project, which is also underway until the year 2017, we see that the project has adopted a different approach that differs from the Pevensey Sea Defence Scheme. The project entails the use of 325,000 tonnes of rock armour ( figurer 2 ) , which are being used to develop a new sea defense that will stand harsh environments (Wyre Council, 2014). When the two projects are critically analyzed, it can be stated that both projects are actually viable in terms of dealing with the problem of flooding and erosion. The Shingle approach is developed using a mix of sand ( diameter 0.06 to 2mm), cobbles (greater than 60mm) and gravel (2mm to 60mm). The materials used can be effective in preventing erosion and flooding. Nevertheless, it essential take note of the fact that the use of the Shingle approach in the Pevensey Sea Defence Scheme is not a very effective approach. Stripling et al, (2008) disclose that the shingle can be overtopped by large waves. In addition, they may leak and roll back and can finally collapse thus resulting to the risk of flooding. The Rossall sea defences project on the other hand can be rated as more effective based on the fact the project entails the use of material that are stronger and more resilient to flooding and strong waves. Figure 2- The Rossall sea defences Project The European commission (2004) proposed the key factors that influence the management of coastal erosion. One of the key concepts is coastal resilience. Coastal resilience is the long – term natural capability to accommodate change without the loss of functions. The Pevensey Sea Defence Scheme has the capability of having the attribute of coastal resilience. This is basically because the project entails long- term management of the sea. The project has adopted the management approach whereby management activities are adopted in order to react to the changes in risk that take place. A key management approach is regular monitoring. The use of monitoring as a management approach corresponds to the national coastal erosion and flood risk management strategy for England (2011). Monitoring is considered as an effective management approach because continued tracking of changes in risk will enable the development of interventions in order to combat the risk. It can therefore be stated that The Pevensey Sea Defence Scheme is effective due to the use of management approaches that can assist in the development of coastal resistance (Sutherland and Thomas, 2011). In comparison to other projects such as the Dunwich coastal defense demonstration project that sought to construct a low cost technique that is able to protect the Dunwich region from erosion. It can be stated that the Pevensey Bay Sea Defence scheme has the capability of being more coastal resilient, thus making it a more effective project. The Dunwich coastal defense demonstration project also involved the use of the shingle approach. The shingles were constructed using a sequence of 90cm x 90cm x 90 cm flexible intermediate bulk containers (FIBCs). A hopper arrangement was constructed for filling in the fabric bags, which were to take up the structure of a compartment( Figure 3). Figure; 3.0 the Dunwich Coastal Defense Demonstration Project Both projects are actually similar due to the adoption shingles approach. However, the Pevensey Bay Sea Defence scheme is more coastal resilient as opposed to the Dunwich coastal defense project due to a number of factors. One of the factors is attributed to the materials used for the construction of shingles. Although the fabric bags used in the Dunwich project are more cost effective, nevertheless the materials are not coastal resilient enough based on the fact that the bags can be destroyed easily essentially when the waves are too strong. The timber groyne used in the Pevensey Bay Sea Defence scheme is more long lasting and therefore more coastal resilient. An additional factor is that the Pevensey Bay Sea Defence scheme is more effective and coastal resilient due to the continuous management of the project through monitoring and dealing with the risks that arise. The Dunwich project was a five year demonstration project that had the objective of showing how low cost material can be used in dealing with erosion. The project however ended. The Pevensey Bay Sea Defence scheme is intended to last much longer and thus making it more effective. White Cart Water Flood Prevention Scheme Glasgow It can be stated that these particular project is effective. This is due to its potential benefit of flood prevention. For closely to a century, the White Cart Water has brought about grave flooding to homes and even property on the Glasgow region. The river has always been fast flowing and prone to flooding essentially when heavy rains occur and the water rises to higher levels. Registers indicate that since 1984 over 500 homes have been affected by the river due to more than twenty floods. Since the commencement of the project in the year 2002, it can be stated that there has been a decline the rate of flooding. For instance, flood events that took place in January 2005 and October 2008 were very close to flooding property; nevertheless, the existence of the project reduced the level of flooding. Although a major flood event took place on February 2011, the existence of the prevention scheme was very useful in alleviating more flooding (Equal, 2013). It is approximated a destruction costing nearly £11 million of would have taken place if these defences did not exist. In comparison to other projects such as the Dunfermline Flood Prevention Scheme, it can be stated that the White Cart Water Flood Prevention Scheme has been useful in flood prevention. Dunfermline Flood Prevention Scheme has faced numerous challenges including the existence of troubled contractors making the project stagnate affecting its objective of flood prevention (Dunfermlinepress, 2014). The White Cart Water Flood Prevention Scheme can also be argued as effective based on its potential capability of holding the backwater when storms take place. The project entails the construction of areas of flood storage (Figure 4) within the rural upstream region in order to hold backwater when a heavy storm takes place. Other similar projects such as Almondbank Flood Protection Scheme have also adopted the approach of the construction of flood storage areas where the water from River Almond can be stored (Perth and Kinross Council, 2014) . It can be stated that flood storage areas is basically an effective way of flood prevention based on the fact that can assist in holding back more than 2.6 million cubic metres of flood water. Figure 4- Flood storage The project also entails the construction of flood defences in the downstream areas of the city. The flood defences entail a 4.5 km wall in river corridors (Figure 5). The flood defenses are usually reduced in length and height, which provide the engineering benefit of ensuring that a barrier is not created between the wildlife and the river. The flood defences are a useful approach of maximize the preservation of the natural flood plain. The Almondbank Flood Protection Scheme has also developed flood defences as a crucial element of prevention (Perth and Kinross Council, 2014).What is evident is that the existence of flood defences in both projects is an effective approach of flood prevention . Figure 5 - Flood defences Annual Coastal Defence Inspection Report- November 2011 The Wyre Borough council Annual Coastal Defence Inspection Report, provides findings concerning annual inspection of flood defence and coastal defence assets in order to evaluate the risk of flooding and coastal erosion. It can be stated that the report is actually an effective way of flood management based on the fact that it examines the various defence approaches that have been established in the area and their potential capability to alleviate flooding and erosion. When defence approaches are subjected to annual reviews then areas of improvement can be identified which will further lead to improvement of the approaches. This will further assist in flood reduction and erosion. For instance, the report identifies the potential causes of failure of the Cleveleys south promenade which includes wave impacts that can cause erosion and the probability of undermining the lower area of the stepped revetment, resulting to breaching of defences In comparison to other inspection reports such as the Flood and Coastal Erosion Risk Management in Wales, 2011, it can be stated that both the Wyre Borough council and Wales report are useful in the management of flooding and erosion. This is because both reports identify areas of deficiencies in the defence approaches and highlight how improvements can be made. Also, it can be stated that the report is effective because it provides an in-depth research concerning the performance of the various projects established in the area. The reports provide both qualitative and quantitative data concerning the performance and the condition of the defences an indication that the findings can be useful in performance improvement. Compared to other reports such as the Flood and Coastal Erosion Risk Management in Wales, 2011, we see that the report does not give much details concerning the performance of the defences , consequently it can be argued that the Wyre Borough council Annual Coastal Defence Inspection Report is more effective and comprehensive . Question 2 Improvement on the White Cart Water Flood Prevention Scheme Glasgow Expansion of the Capacity of Flood Storage areas One of the key areas of improvement for this particular project is to increase the capacity of flood storage areas. In 2011 February 4th as the construction was in progress, the project was put to a great test based on the fact that the flood in this year was immense. Equal (2013) discloses that 10% of the flooding was significantly reduced based on the fact that the storage areas were operational, thus a great deal of damage was prevented. However, it is essential to put into consideration of the fact that climate change is a real problem today and therefore it can be difficult to estimate the level of future floods. Although the project has established a substantial number of flood storage areas, it is therefore essential to expand the capacity of the flood storage areas. Expanding the capacity of the flood storage area is designed to avert higher levels of flood that can take place if the existing storage volume is reduced. Higher levels of flooding would definitely bring about an impact on properties that are nearby, downstream or upstream. The mapping approach can be used as a strategy for filling the flood storage area. The allowable percentage of fill is between 35% to 65%. This percentage relates to the existing percentage of storage volume that can be filled without reaching the 100-year flood height. For instance, in the event that the storage area is to hold a capacity of 50% acceptable fill , this means that only 50% of the volume of flood storage is confined within the storage area, thus only the 50% can be filled while the other 50% of the volume of storage must be preserved (Watershed Management , 2006) . Normally, the capacity of a storage facility is usually lowered by the failure to raise the land above the level of the flood vessels. It is therefore essential to raise the land above the flood vessels through filling. This will improve the capacity of the storage area and thus enhance its usability essentially when the level of flooding increases. Figure 6 demonstrates the flood storage area before rising its level, while figure 7 displays Flood Storage area after Expansion. Figure 6; Flood Storage area before Expansion Figure 7; Flood Storage area after Expansion Question C – Reflection During the seminar session, the participants asked various questions. The questions did not deviate from the topic but were rather related to the information provided by the presenters. It can be stated that the questions asked were good and effective essentially based on the fact that they assisted in the better understanding the information presented. I also asked questions that were comprehensively answered by the presenter, however there are certain questions that I did not manage to ask due to the time limits. The questions asked by other participants were also effectively answered by the presenters, who explained the facts precisely. I also took note of the fact that the questions asked by other participants were not very clear which gave the presenter difficulty when it comes to responding to the questions. The presenters on the other hand explained their content in a logical and organized manner. I was therefore able to understand the facts presented effectively, although some of the presenter did not expand their explanations due to limited time. Conclusion The discussion above has presented an evaluation of various projects and an inspection report which have the objective of reducing flooding and erosion. After in-depth examination of the projects it can be stated that the initiative are effective in attaining the intended objectives. It is therefore essential that the projects are effectively implemented. References Dunfermlinepress, 2014, New contractors named for troubled Dunfermline flood prevention scheme, Dunfermlinepress. Environment Agency , 2013, Dunwich coastal defence demonstration project, Defra. Pevensey Coastal Defence Ltd, 2014 , Pevensey Bay Sea Defences , http://www.pevensey-bay.co.uk/ppp.html Stripling, S., Bradbury, A.P., Cope, S.N., Brampton, A.H, 2008, Understanding Barrier Beaches. Joint Defra/EA Flood and Coastal Erosion Risk Management R&D Programme, R&D Technical ReportFD1925/TR. Internet: available from http://sciencesearch.defra.gov.uk Equal LTD, 2013, White Cart Water Flood Prevention Scheme, Retrieved From Perth and Kinross Council, 2015, Almondbank Flood Protection Scheme, Perth and Kinross Council. The Flood and Coastal Erosion Risk Management in Wales, 2011, Retrieved From < http://naturalresourceswales.gov.uk/content/docs/pdfs/flooding-and-alerts-pdfs/flood-and-coastal-erosion-risk-management-in-wales-2011-2014.pdf?lang=en> Watershed Management , 2006, Flood Storage Areas , Watershed management.   Wyre Council, 2014 , Rossall Sea Defences, The District Council network . Retrived Form http://districtcouncils.info/casestudies/rossall-sea-defences/ Sutherland, J and Thomas, 2011, James and Ian The management of Pevensey shingle barrier, Published in the Journal of Ocean and Coastal Management 54 (2011), pp. 919- 929. Read More