Neighborhood Coastal Stormwater Design: A Building Block for Resilient Communities
The 2023 Infrastructure Report Card prepared by the American Society of Civil Engineers reported that national stormwater infrastructure earned a grade of “D”.
The increasing need for stormwater retrofits and new stormwater infrastructure to combat more intense rainfall due to climate change is complicated by the fact that most of the high priority projects are in densely populated areas with extensive existing infrastructure. A strategy to prepare for such challenges is needed as resilient planning and design become priorities, especially for coastal communities.
Municipalities have used stormwater master planning or tracking areas of recurrent flooding to identify high priority stormwater projects. Most identified project areas pose design and construction challenges because of space constraints. The goal is to address flooding issues in an organized fashion with reasonably sized projects that do not overwhelm resources and strain budgets. Like the City of Newport News, many Hampton Roads communities are planning for and funding neighborhood-level stormwater projects to tackle flooding issues. These projects propose infrastructure to meet the level of service, which likely considers more intense rainfall due to the changing climate.
The Colberts Lane Drainage Improvement Project in Newport News, Virginia is an example of one such neighborhood stormwater project. This neighborhood is characterized by a low-lying, tidally influenced residential street with roadside ditches, driveway culverts, and limited stormwater infrastructure to capture and convey stormwater runoff. The approach to designing the stormwater system to meet the level of service was met with obstacles like constructability issues between homes; channel grading restrictions along property lines; and increased costs to repair water and sanitary infrastructure impacted by the proposed stormwater construction.
These considerations and obstacles will become more frequent as SW projects are proposed to mitigate the effects of climate change. Lessons learned and an overall strategy to prepare and plan for these challenges in design and implementation.
The intended result is municipalities that can build resilient stormwater infrastructure in coastal and densely populated areas with a realistic plan and cost to address construction challenges. This allows municipalities to collectively work on improving national stormwater infrastructure one neighborhood building block at a time.