Stormwater Issues at Multi-family Properties

Managing stormwater on multi-family properties involves various challenges. These properties face unique issues, from sharing stormwater infrastructure to high-density areas with minimal green areas. Addressing these challenges requires careful planning and management to promote a healthy and safe residential environment.

The Challenge of Sharing Infrastructure

One of the common stormwater issues faced by multi-family properties is the stormwater infrastructure they must share with other entities, such as neighboring residential properties or municipalities. This characteristic creates multiple challenges in creating a cohesive system management plan. For example, properties might experience localized flooding due to issues with combined drainage systems and parts of the system they do not control.

Coordinating regular maintenance is challenging because the maintenance program must run across multiple tenants or owners. Additionally, the collective responsibility for the system makes it more complicated to secure funding for necessary system repairs and upgrades. Within a shared system, some areas may contribute higher runoff volumes than others, further complicating stormwater management. Overall, stormwater system managers have their hands full with the challenges of implementing a stormwater management plan that is cohesive enough to address all these issues.

Parking Lot Issues

Multi-family properties typically have large parking lots, which can contribute significantly to the pollution that washes away with stormwater runoff, requiring a careful management approach. One of the main culprits is the oil from vehicles parked in the lots. Exhaust emissions and micro-particles from car tires are other examples of pollutants that run off with stormwater during a rain event. Likewise, car engines leave behind heavy metal deposits, such as zinc and copper, that flow into the stormwater drainage system and, ultimately, to local water bodies.

Parking lots can accumulate large quantities of dirt and debris, increasing the sediment in runoff. Other chemicals, such as antifreeze or brake cleaner products, can also be carried away in runoff. Drivers may also throw garbage out of their cars into the parking lot. Regular storm drain cleanout is crucial in parking lot areas to prevent drains from clogging due to sediment buildup, parking lot garbage, organic matter, and other debris.

Roof Runoff Problems

The runoff volume from roof areas in multi-family complexes requires skilled and consistent management to prevent flooding and property damage. Multi-family buildings often have extensive roof areas, generating significant runoff during rain events. Different roofing materials can affect the runoff volume and contribute to additional pollutants that impact the runoff quality.

Common stormwater issues multi-family properties face include poorly maintained rain gutters, which can overflow. This outcome can lead to damage from water seeping underneath the roofing or into other areas of the buildings. In addition, downspouts can create concentrated discharge points, contributing to flooding and erosion in localized areas.

Limited Green Areas

Multi-family properties often have high-density development, which means the green space, such as grassy areas, is frequently limited. The lack of grassed regions affects the property's stormwater absorption capacity, making it harder to manage. Property management guidelines or HOA rules may also limit the types of landscaping permitted, adding further complexity to the issue.

Minimal green space and many impervious surfaces, such as sidewalks and parking lots, lead to higher runoff due to the lack of permeable areas that can stop stormwater and allow it to sink in. Additionally, meeting the green space requirements for regulatory compliance can be challenging for multi-family properties' dense building layouts.

Landscaping Damage and Erosion

After storms, multi-family properties with inadequate stormwater drainage systems often suffer soil erosion and landscaping damage. Sloped properties can develop eroded areas due to runoff, leading to unstable ground. Additionally, excessive runoff can lead to soil erosion around plant roots, damaging them and reducing vegetation's health.

Poorly maintained retention ponds on properties can overflow due to excessive runoff, which leads to erosion in the surrounding areas. Likewise, drainage ditches that are poorly maintained or inadequate can overflow and contribute to eroding soil. Finally, runoff and erosion can undermine and damage paved areas like patios and walkways.

Issues with Foundations and Basements

The foundations and basements of multi-family properties are at risk of damage due to infiltrating stormwater, which can cause significant and costly problems. High runoff volumes can result in pooling water that seeps into basements, which can cause flooding and mold growth. Sump pumps can also fail during heavy storms, another cause of basement flooding.

Additionally, inadequate grading around buildings can weaken and damage foundations by directing water toward them, resulting in persistent water exposure. Pooling water around building foundations can promote mold growth by raising interior humidity levels.

Complying with Various Regulations

One significant aspect of multi-family property stormwater management is navigating the complexities of regulatory and compliance issues. Properties must maintain regular inspections and reporting to ensure they stay in compliance. However, keeping up with the constant changes in stormwater management best practices and required regulations can challenge multi-family property system management.

If a stormwater system is not compliant, the property may risk fines and enforcement actions from the local authorities. To complicate matters, updating a system to remain compliant may become challenging due to the time-consuming nature of obtaining the necessary permits to modify the stormwater management system. Additionally, local zoning laws may limit the type of stormwater management practices the property can implement.

Retaining and Detaining Stormwater

Stormwater retention and detention ponds are valuable components of an overall stormwater management system, but the limited space and shared responsibility of multi-family properties make managing these components challenging. Due to their high-density building areas, multi-family properties often have limited space for adequate ponds.

Additionally, existing ponds can become neglected, especially when multi-family properties share the responsibility for maintenance with other entities. When ponds are poorly maintained, the standing water can become a breeding ground for mosquitoes. Ponds may also require additional safety measures to minimize risks to young children and pets, and complying with local stormwater regulations regarding retention and detention ponds can be challenging.

A Complex Drainage Network

Maintaining the complex drainage network required for multi-family properties involves regular maintenance, skilled repairs, and inspections to keep the system functioning. Multi-family property systems may also have multiple stormwater outlets, which makes maintenance and management more challenging.

Multi-family properties' common stormwater issues include complicating factors such as outdated drainage systems, which can increase backups and blockages. Obsolete systems may also need help handling increasingly severe storms' runoff volume. Other challenges include properties that have subsurface drainage systems, which add additional complexity for maintenance and inspections.

Participation of Residents and Tenants

Residents and tenants can behave in ways that hinder the effectiveness of a multi-family property's stormwater management plan and practices. Building awareness and education regarding stormwater management is crucial. Otherwise, tenants may dispose of waste in ways that clog drainage systems or make unauthorized modifications to drainage on the property, leading to system failures. Additionally, washing cars in the property's parking lot or improperly disposing of pet waste in common areas can add pollutants to stormwater runoff.

Awareness is the Key to Effective Stormwater Management

Stormwater management for multi-family properties is complex and multifaceted, requiring expertise and consistent effort. CatchAll Environmental has the experience and knowledge to help put your stormwater system management on auto-pilot. Contact us today to ensure your property stays compliant and safe from stormwater issues!