Stormwater Management

As with all of my engineering consultation/designs, you will be presented with a detailed written proposal of the scope of work for your review, including fee, prior to commencing.

Stormwater runoff is precipitation from rain/snowmelt that does not soak into the ground. This nonpoint source pollution is in the form of sediments, nutrients, chemicals, oil & grease, organic matter, and litter. As it is collected and transported, it picks up pollutants as it flows to the streams and lakes. For this reason, municipalities all now have ordinances to combat this phenomenon; typically low-cost, low-maintenance best management practices (BMP’s), therefore a new lot will be required to meet the standards of the Stormwater ordinance, which may also include the preparation of a Stormwater Management Report.

To ensure that there is no net increase in stormwater runoff as a result of your proposed project, typically for homeowners the remedy in the  form of a drywell, which treats/stores the “clean” rainwater runoff from the roof. Other impervious surfaces are considered “dirty” (i.e. driveways), and that runoff is retained or slowed down via BMP’s such as infiltration basin. To meet the SWM requirements, BLSH&E will:

• Coordinate/conduct a topographical survey to determine the ground elevations, contours, and grade (steepness) at the project location. 
• Sometimes the municipality may require a soil log (an exploratory test of the soil conditions) for the purposes of design, and sometimes this can be waived until it comes to construction.
• In either case, BLSH&E designs the drainage structure to treat the appropriate storm event as per municipal and/or State regulations, and provides calculations in support.
• Typically, the ground contours need to be modified in order to accommodate the recommended structure. This entails re-grading the property, and may require the preparation of a soil transport application (and possible approval from the local Soil Conservation District).
• Prepare the necessary plans, details, and specifications; submit municipal engineer for review and approval.
• Upon approval, assist the homeowner with contractor selection. Construction oversight services may also be provided to perform various inspections to ensure project is built according to plan, approve contractor requests for payment, and sign off on the final punch list. 

Typically, SWM is not a "stand-alone" design service, but more of a component of the larger picture, such as a site plan. BLSH&E can guide you through it; give me a call today.