Best Management Practices (BMPs)- Inlets, Outlets & More

Bioretention, Bioswales & Vegetated Filter Strip Inspections

The usage of stormwater treatment plans, often referred to as Best Management Practices (BMPs), has increased significantly due to additional stormwater laws.  

These regulations require a developed systematic approach for BMP inspection and maintenance documentation since BMPs require ongoing assessment and maintenance to guarantee desired treatment goals.  

There are various resource guides and supplemental manuals regarding local government inspections and maintenance activities associated with multiple BMP categories. This reference guide focuses on Bioretention, Bioswales, and Vegetated Filter Inspections and describes the BMPs and a list of some applications for further exploration.  

Inlets & Outlets

As you assess your inlets and outlets for your Bioretention, Bioswales, and Vegetated Filter Strip Inspections, note the structural integrity and the amount of debris. You want to make sure you’re clearing all debris and that your structure is intact and stable on an annual and monthly basis. 

 Likewise, annually, you want to check for signs of erosion to your Bioretention inlets (rock or mat) and outlets and inspect and clean your BMP upstream basin every five years.


For annual pretreatment services, make sure to evaluate sediment trapping devices and remove any accumulated deposits.  

 In particular, for Bioswales and Vegetated Filter Strip Inspections, assess evidence of erosion and water flow going around structures annually. You want to maintain a clear flow to prolong your system’s sustainability.   

Overall Functionality

Maintaining the overall functionality of your Bioretention and Bioswales should be monitored annually via a professional civil engineer. Sometimes, minor specific details regarding your regulations and requirements can make or break your entire inspection. 

 Thus, it’s crucial to hire and utilize a PE or a commercial stormwater management company with the network to reach out to such individuals readily accessible.  

Bioretention & BMP Surface Areas

To properly inspect your Bioretention or BMP surface area, remove debris accumulation monthly and remove sediment deposits annually. This approach will help detect evidence of erosion and help improve vegetative cover. 

 Additionally, you can add mulch covers to your specified level of thickness annually regarding your Bioretention surface area as well. Again, your engineer or stormwater management company can help determine this need.

Optional Enhancements

Other annual considerations you should undertake during your Bioretention, Bioswales, and Vegetated Filter inspection process should involve keeping an eye out for any invasive species that may disturb your system.   

 Connecting with a qualified professional can help detect unwanted invasive bugs and plants and can help apply a selective herbicide to treat your area. They can also increase the diversity of your vegetation, improving aesthetics and mitigating potential residential complaints.   

We recommend performing your BMP inspections by a licensed PE or specialized commercial contractor to safeguard the design and function of your ponds or stormwater drainage system.  

Contact your partner or specialist to discuss your options and for other necessary next steps.   


Ferrandino & Son, Inc. delivers commercial stormwater management services to multi-site portfolios across the country. To learn more about Ferrandino & Son, visit or email us at