As-built surveys

Throughout the construction process, it is sometimes necessary to deviate from the intended design of LID features and adapt the design to on-site conditions. The completion of a post-construction as-built survey is a standard operating procedure for engineering projects that captures any changes made to the feature’s design during construction.<sb>

Survey Steps:

1. Use the same datum as the pre-engineering survey
2. If a pre-engineering survey is not available, use a reference feature as the datum
3. Identify the type, diameter, and material of exposed utilities
4. Include data on critical feature elevations and existing utilities, such as:

• Inverts of newly installed pipe
• Vertical and horizontal bends in pipes
• Existing public utilities
• Existing private utilities
• New and existing structures (e.g., catchbasins, manholes, chambers, etc.)<sb>

Inspection Points:<sb>

• Datum matches the pre-engineering survey or selected reference feature
• Data provided in as-built survey matches the as-built standards of the local municipality<sb>

Low Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.