Lot-level practices to control urban flood risk and mitigate basement flooding in Canada

地下室洪水造成的水损害是加拿大家庭保险索赔的最大来源之一。近年来，与地下室洪水有关的经济损失急剧增加。今天，据估计，加拿大每年因地下室洪水造成的水损害保险损失约为18亿美元。极端降水事件、城市化和土地利用的变化，以及市政基础设施(如下水道系统)的年限和状况的增加，加剧了对地下室洪水的敏感性和保险损失的增加。地下室淹水主要是由于卫生或雨水下水道系统不足或地基和地块排水系统不足造成的，可能是渗透、陆上洪水和下水道备份造成的。许多因素影响地下室洪水的发生，包括雨水管理基础设施和保护房屋免受地下室洪水影响的地块级别的技术或方法。地块层面的方法可以包括地基排水系统(例如，渗漏瓦片系统)以减少渗透洪水的发生，低影响开发措施(例如，生物沟、渗透沟等)。以减少陆上淹水的发生，以及回水阀门以减少下水道倒灌的发生。这项研究的目的是评估各种技术和方法的性能，以降低发生地下室淹水的风险。特别是，这项研究将调查回水阀的性能，以降低因下水道超载而导致的地下室淹水风险，并评估低影响开发措施在改善城市排水和下水道网络对极端事件的响应方面的效果。结果将与保险公司、市政当局、管道行业、工程咨询公司和加拿大房主相关。这项研究将有助于发展加拿大的住房和社区，使其对城市洪水事件的不利影响更具弹性，并将寻求减少地下室洪水造成的经济损失。

Water damage due to basement flooding is one of the largest sources of home insurance claims in Canada. A drastic increase in economic damages associated with basement flooding has been observed in recent years. Today, it is estimated that approximately $1.8 billion in insured losses for water damage due to basement flooding is incurred every year in Canada. The sensitivity to basement flooding and increased insured losses are exacerbated by the increase in frequency and magnitude of extreme precipitation events, urbanization and changes in land-use, and the age and condition of municipal infrastructure (e.g., sewer systems). Basement flooding, which primarily occurs due to inadequate sanitary or storm sewer systems or insufficient foundation and lot drainage systems, can result from infiltration, overland flooding and sewer backup. Numerous factors influence the occurrence of basement flooding, including stormwater management infrastructure and lot-level technologies or approaches that protect homes from basement flooding. Lot-level approaches can include foundation drainage systems (e.g., weeping tile systems) to reduce the occurrence of infiltration flooding, low impact development measures (e.g., bio-swales, infiltration trenches, etc.) to reduce the occurrence of overland flooding, and backwater valves to reduce the occurrence of sewer backup. The goal of this research is to evaluate the performance of various technologies and approaches to reduce the risk of occurrence of basement flooding. In particular, this research will investigate the performance of backwater valves to reduce the risk of basement flooding due to sewer surcharge and evaluate the effect of low impact development measures on improved urban drainage and sewer network response to extreme events. Results will be of relevance to insurance companies, municipalities, the plumbing industry, engineering consulting companies and Canadian homeowners. This research will assist in developing Canadian homes and communities that are more resilient to the adverse effects of urban flooding events and will seek to reduce the economic damages experienced as a result of basement flooding.