Landscaping, Maintenance
& Retrofit Guidance

Section 1 - Landscaping and Vegetation Considerations (Chapter 7)

Landscaping and Vegetation Considerations (Chapter 7)

1.1 Planting Goals

Chapter 7 treats vegetation as a functional part of a stormwater management measure rather than as ornament alone. Across the two editions, the chapter clearly supports several recurring planting goals:

• use native or otherwise non-aggressive species suited to New Jersey conditions, because local adaptation improves survivorship and reduces replacement maintenance
• match plant selection to the BMP's hydrologic conditions, because different areas of a facility experience different inundation depths and durations
• use vegetation to stabilize shorelines, slopes, channels, spillways, and other erosion-prone areas
• use vegetated cover and filter strips to slow runoff and filter sediment before it reaches the main treatment area
• plan vegetation with long-term maintenance access in mind, keeping access routes and maintenance areas clear enough for future inspection and upkeep

1.2 Vegetation Roles in BMP Performance

Chapter 7 organizes planting around hydrologic zones and plant tolerance rather than around one universal planting palette. The chapter explains that stormwater facilities may include deep water, shallow marsh, shoreline fringe, floodplain bench, and upland slope conditions, and that successful planting depends on putting species in the zones they can actually tolerate.

The chapter also supports several practical vegetation-management concepts that belong in a maintenance-oriented report:

• native species are favored because they are better adapted to local climate and generally reduce replacement needs over the life of the facility
• introduced or aggressive species can become invasive and displace desired vegetation; Chapter 7 discusses examples such as phragmites and purple loosestrife as management concerns
• water control and weed control are especially important during the establishment year
• monitoring for several years after the establishment year can help maintain the planting and improve future planting decisions

Chapter 7 also includes siting cautions that matter for long-term maintenance. It advises against planting trees or shrubs with long taproots near dams or subsurface drainage facilities and calls for setbacks from dam toes and perforated pipes so vegetation does not create structural or access problems later.

1.3 Differences Between the 2023 and 2026 Manuals (Chapter 7)

For the Phase 2A source set, the comparison is continuity-heavy rather than a major chapter-level change.

• Chapter 8 is textually identical across the 2023 and 2026 source chapters in this corpus.
• Chapter 7 carries the same substantive framework in both editions for native/non-aggressive planting, hydrologic-zone selection, establishment-year water and weed control, invasive-species caution, and long-term vegetation management.
• Chapters 7 and 8 themselves present that framework in general maintenance terms rather than through one statewide set of numeric vegetation thresholds or inspection intervals.

Where a project needs those kinds of numeric or practice-specific rules, the authority must come from the practice chapter or other source that actually provides them.

Section 2 - Routine BMP Maintenance (Chapter 8)

Routine BMP Maintenance (Chapter 8)

2.1 Inspection Frequency Concepts

Chapter 8 clearly establishes that all stormwater management measures in a major development need a maintenance plan and that the plan must include a schedule of regular inspections and tasks. It also requires that the plan identify the responsible party, include cost estimates, and maintain detailed logs of preventative and corrective work.

The same chapter also states that, once the plan is completed:

• copies must be provided to the owner and operator and submitted to reviewing agencies
• the plan title, date, and responsible party information must be recorded on the deed
• the person with maintenance responsibility must evaluate the plan for effectiveness at least annually and revise it as needed
• detailed written logs of inspections and maintenance work must be kept
• the plan and associated records must be retained and made available on request to public entities with authority over the site

Those points support scheduled, documented inspection and annual plan review. Chapter 8, however, leaves detailed BMP-specific inspection tasks and schedules to Chapter 9 and the NJDEP maintenance manual rather than imposing one fixed statewide cadence for every BMP.

2.2 Sediment, Debris, and Vegetation Management

Chapter 8 supports a general maintenance framework rather than a single statewide schedule. It requires maintenance plans to address tasks such as:

• removal of sediment, trash, and debris
• mowing, pruning, and restoration of vegetation
• restoration of eroded areas
• elimination of mosquito breeding habitats
• control of aquatic vegetation
• repair or replacement of damaged or deteriorated components

The chapter also requires maintenance planning around access, training, safety, and disposal. BMP components must remain accessible for inspection and maintenance, perimeter vegetation may need pruning to preserve access, and the maintenance plan should identify approved disposal or recycling procedures for removed sediment, trash, debris, and other material.

Within Chapters 7 and 8 themselves, maintenance remains a framework of responsibilities, access, recordkeeping, vegetation management, and repair rather than a universal list of numeric cleanout triggers, mulch depths, mowing heights, or post-storm inspection rules. Those details may exist for specific BMPs elsewhere in the corpus, but they are not stated as universal Chapter 7 or Chapter 8 requirements.

2.3 Practice-Specific Examples from Other BMP Chapters

Several BMP-specific chapters do set numeric inspection and maintenance schedules for particular practices.

For example, 2026_BMP_10.1_LargeScale_Bioretention_Systems requires:

• annual inspection of structural components
• inspection of debris- and sediment-trapping components at least four times annually and after storms exceeding 1 inch of rainfall
• underdrain piping that remains accessible for inspection and maintenance
• bi-weekly inspections during vegetation establishment or restoration

Those are useful operational details, but they belong to the specific practice chapter rather than to Chapter 8 as a universal maintenance rule.

Section 3 - Retrofit and Long-Term Management (Chapter 8)

Retrofit and Long-Term Management (Chapter 8)

3.1 Upgrading Existing BMPs

Chapter 8 defines retrofitting broadly as expanding, modifying, or otherwise upgrading existing stormwater management measures. In both editions, the chapter says retrofitting can reduce adverse groundwater recharge and stormwater quantity and quality impacts associated with existing development.

The chapter gives a practical reason for retrofit work: many older detention facilities were built mainly to address larger quantity-control storms, while smaller storms responsible for water-quality and streambank-erosion problems may not have been addressed well. Chapter 8 therefore supports retrofits that improve how older facilities handle those smaller events.

It also identifies several reasons communities may pursue retrofit work:

• to correct site nuisances, maintenance problems, or aesthetic concerns
• to keep pace with newer stormwater objectives or regulations
• to address a quantity or quality problem identified through a regional plan or TMDL
• to improve existing measures when building entirely new facilities is impractical

Once a retrofit is found to be appropriate, Chapter 8 says there are two basic approaches: modify an existing measure or construct a new or additional one. The chapter gives examples such as enhancing an existing detention basin, adding infiltration systems, using permeable paving, or introducing bioretention where soils and seasonal high water table conditions are suitable.

The retrofit discussion in the source corpus is continuity-heavy across both editions. The chapter presents retrofitting as an established way to improve older facilities rather than as a new 2026-only GI conversion pathway.

3.2 Long-Term Management Considerations

Chapter 8 identifies three major factors that must be considered before retrofitting: health and safety, effectiveness, and maintenance.

Health and safety: a retrofit must not increase risk. The chapter gives examples such as not reducing detention storage for water-quality enhancement if doing so would worsen downstream flooding or erosion, and not converting a functioning wet pond to a constructed wetland if mosquito risk would materially increase without added controls.

Effectiveness: the chapter says some retrofits may not be able to meet every current standard absolutely. In those cases, the retrofit should be judged on relative improvement, viability, and cost rather than on an unsupported assumption that every existing BMP can be brought fully into line the same way.

Maintenance: the chapter warns that a retrofit that captures more pollution may also capture more sediment, trash, debris, and potentially lower-quality material. Added components can also raise the level, frequency, complexity, and cost of inspection and maintenance. Increased staffing, equipment, or specialized training may be needed, and those added burdens should be evaluated before a retrofit is selected.

Section 4 - Key Updates Between the 2023 and 2026 Manuals

Key Updates Between the 2023 and 2026 Manuals

4.1 Implications for Maintenance Planning

The strongest takeaway is that the four Phase 2A source chapters are continuity-heavy. Maintenance planning should therefore be anchored in the duties those chapters actually state:

• identify who is responsible
• define preventative and corrective tasks
• include inspection schedules and cost estimates
• keep detailed maintenance and inspection logs
• record the plan information on the deed
• evaluate the plan annually and revise it when needed
• retain the plan and records for review by the relevant public authority

The landscaping side of maintenance planning should likewise stay grounded in what Chapter 7 actually says: select plants by hydrologic zone, favor native and non-aggressive species, manage water and weeds during establishment, and preserve long-term access for inspection and upkeep.

When a project needs BMP-specific schedules, numeric thresholds, or detailed operational procedures, the safer method is to cite the relevant practice chapter or other source directly and label that authority explicitly instead of attributing it to Chapters 7 and 8.

End of Phase 2A Maintenance Content Source reference: NJ Stormwater BMP Manual, Chapters 7-8, 2023 and 2026 editions; broader-corpus fallback labeled where used.