Description
The Town has partnered with Thomas and Hutton to perform a multi-year comprehensive stormwater system evaluation of the Old Village. The study area was broken into 27 drainage basins or areas of land that drain to a common point. The level of service for each basin was determined by comparing system capacity to projected peak runoff during a storm.
The Town currently uses a ten-year storm event as the design standard for new stormwater systems. A ten-year storm event has a ten percent chance of being equaled or exceeded within a one-year period. Thomas and Hutton used the ten-year storm as the benchmark for level of service even though these existing systems were put into service well before a design standard was adopted. Thomas and Hutton then ranked all the drainage basins in order of priority to receive upgrades.
This priority ranking was based most heavily on each basin's level of service but also considered criteria such as drainage area, requests for services, FEMA flood claims and number of parcels in the basin. The Royall Avenue Basin was ranked first and the Edwards Park Basin was ranked second out of 27 basins. These two basins were selected to enter the design phase where construction documents were developed. Since the Royall Avenue Basin is the highest priority, it will be constructed first.
The proposed system will provide a ten-year storm level of service. However, many homeowners will still see ponding during heavy rain events and flooding could occur if the 10-year design storm is exceeded. The biggest change will be how quickly the water level recedes. Also, areas that previously relied solely on infiltration will now be connected to the new drainage system. Our goal is to limit flooding impacts to structures. Ponding in yards is anticipated during more intense storms.
The original drainage systems incorporated shallow roadside swales. Over time, many of these swales have filled in. In many cases, homeowners added street parking in these areas. As part of this project, many of the swales will be restored within the right-of-way. Homeowners should maintain these areas to help their lots drain and also to help their upstream neighbors' lots drain.
The construction will include installing new pipes, upsizing old pipes, and re-establishment of swales. Replace with, the town has averted the removal of any large trees in the design. Impacts to root systems will be carefully evaluated and monitored by an Arborist to ensure every effort is made to protect the health and lifespan of all trees near the project site. To see a map of the project area, please click this link:
Status (As of January 26, 2021)
- Design and permitting complete
- In the process of preparing the Bid Package
Schedule
- TBD
Cost
Design Cost: $880,265.00
Resources
View the Old Village Watershed Study
Contact
Kevin R. Mitchell, PE
- Ph: (843) 856 - 3080