Bridging the Gap: Ensuring Long-Term Success of Stormwater BMPs in the U.S.

Stormwater management in the United States has undergone significant technical and regulatory advancement over the past several decades. Hydraulic modeling, water-quality treatment design, and Best Management Practice (BMP) standards are more refined than ever, and many engineers already design systems with long-term functionality in mind. Maintenance access, sediment forebays, stabilization measures, and vegetative performance are routinely considered during plan development.

Yet despite these advances, a persistent gap remains—not in engineering capability, but in how stormwater systems transition through ownership and long-term stewardship. Across federal, state, and local jurisdictions, stormwater BMPs are often well-designed, properly permitted, and correctly constructed, but their long-term performance becomes uncertain once responsibility is transferred beyond the permitting phase. This challenge is not a reflection of inadequate engineering; rather, it is a systemic issue rooted in governance, funding alignment, and awareness during ownership transfer.

As regulatory expectations for water quality continue to increase, addressing this continuity gap will be essential to meeting compliance goals and protecting downstream resources.

Strong Design Practices, Limited Lifecycle Alignment

Many stormwater engineers already account for maintenance during design. Standard details include stabilized outlets, access benches, sediment capture zones, and vegetation schemes intended to support long-term performance. Design manuals at the state and local level frequently contain maintenance guidance, and operation and maintenance (O&M) plans are commonly required as part of permit approval.

At the federal level, the U.S. Environmental Protection Agency establishes national water-quality objectives and delegates stormwater implementation through programs such as the National Pollutant Discharge Elimination System. These programs focus primarily on ensuring that BMPs are installed according to approved plans and that construction-phase impacts are controlled.

State agencies, including the South Carolina Department of Health and Environmental Control and similar authorities nationwide, translate federal guidance into design criteria, permitting standards, and inspection protocols. Local governments then apply those standards during development review and construction acceptance.

In many cases, this system functions well through project closeout. The challenge emerges later, when BMPs transition into long-term ownership and operation.

Where Performance Risk Emerges: Ownership Conveyance

The most common point of BMP performance degradation occurs after construction—during ownership transfer. This transfer may involve conveyance from a developer to a homeowners association (HOA), dedication to a local government, or long-term private ownership by a commercial or residential property owner.

During this transition, several factors converge:

• Maintenance plans are recorded but not actively implemented
• Funding mechanisms for future maintenance are limited or absent
• Institutional knowledge diminishes as boards, managers, or owners change
• Inspections shift from proactive to complaint-driven

These outcomes are rarely the result of disregard. In many cases, HOAs and property owners are unaware that they now own regulated stormwater infrastructure. BMPs are frequently perceived as landscape features rather than functional treatment systems with defined performance expectations.

Unlike floodplain determinations—which are reviewed during property purchase and directly tied to insurance and lending decisions—stormwater BMP ownership is not consistently recognized during real estate transactions. As a result, long-term maintenance responsibilities may not be fully understood until deficiencies become visible or enforcement actions occur.

Observations From the Field: Education and Preparedness Gaps

This ownership disconnect becomes especially clear during community engagement and professional outreach. During stormwater “Lunch and Learn” sessions with property managers, HOA board members, and municipal staff, a recurring theme consistently emerges: communities are concerned not only about BMP conditions, but also about their lack of education, preparedness, and funding clarity.

These discussions frequently reveal that many communities do not know:

• What BMPs they own
• What condition those systems are in
• What maintenance tasks are required annually versus cyclically
• How much future maintenance is likely to cost
• What steps to take before a system becomes noncompliant

In many cases, funding decisions are reactive rather than planned. Maintenance is deferred because priorities are unclear, reserve studies do not account for stormwater assets, or boards are uncertain how to evaluate competing needs. This is not a failure of intent—it is a lack of accessible, actionable guidance at the ownership level.

These conversations underscore that education and preparedness are as critical to stormwater performance as engineering and regulation. Without a clear roadmap, communities struggle to translate maintenance obligations into practical action.

Stormwater BMPs as Decentralized Infrastructure Assets

From an engineering perspective, stormwater BMPs function as decentralized infrastructure. They attenuate flows, remove pollutants, stabilize channels, and support watershed-scale water-quality objectives. Like any infrastructure asset, their performance depends on routine inspection and maintenance. Sediment accumulation reduces effective storage volume, vegetation changes alter nutrient uptake and slope stability, and structural components degrade over time. These processes are expected and predictable—they are part of the BMP lifecycle, not indicators of poor design.

When maintenance is deferred, BMPs typically decline gradually and then require corrective action under compressed timelines. Emergency dredging, slope repairs, outlet rehabilitation, and regulatory responses often cost significantly more than routine maintenance performed incrementally over time.

Recognizing BMPs as long-term assets, rather than static site features, is critical to sustaining performance and controlling lifecycle costs.