Planning a Home Addition in Montgomery or Chester County? Here’s What You Need to Know About Stormwater Management
Embarking on a home addition in Montgomery or Chester County, PA? Whether it’s a luxurious sunroom, an expansive garage, or a bespoke in-law suite, understanding stormwater management requirements is crucial to ensure a seamless construction process.
In municipalities like Collegeville, Upper Providence, Blue Bell, Phoenixville, and West Vincent Township, stormwater regulations are in place to protect the environment and your property. Navigating these requirements can be complex, but with the right guidance, your project can proceed without a hitch.
Understanding Stormwater Management
Stormwater management involves controlling and directing rainwater runoff resulting from impervious surfaces like roofs, driveways, and patios. Without proper management, runoff can lead to:
- Soil erosion and landscape damage
- Basement flooding and structural issues
- Pollution of local waterways
- Legal complications with neighboring properties
Implementing effective stormwater solutions not only ensures compliance with local ordinances but also enhances the longevity and value of your home.
Local Regulations and Requirements
Each township has specific guidelines for stormwater management:
- Collegeville Borough: Requires adherence to the MS4 program, focusing on reducing runoff and improving water quality.
- Upper Providence Township: Mandates stormwater plans for projects adding impervious surfaces.
- Whitpain Township (Blue Bell): Enforces stormwater controls for developments exceeding specific thresholds.
- Phoenixville Borough: Implements a comprehensive stormwater management program to mitigate urban runoff impacts.
- West Vincent Township: Emphasizes sustainable practices in their stormwater management standards.
Understanding and complying with these regulations is essential. Our team at Merman Construction is well-versed in local codes and can assist in developing compliant solutions.
Effective Stormwater Solutions
Several strategies can be employed to manage stormwater effectively:
- Rain Gardens: Utilize native plants to absorb runoff, enhancing aesthetics and functionality.
- Permeable Pavers: Allow water to infiltrate through surfaces, reducing runoff volume.
- Dry Wells: Underground structures that collect and slowly release stormwater.
- Infiltration Trenches: Gravel-filled ditches that facilitate water absorption into the ground.
- Rain Barrels: Collect roof runoff for reuse in landscaping, conserving water.
Implementing these solutions not only meets regulatory requirements but also contributes to sustainable living.
The picture above is a real Montgomery County home like many we help remodel to add space, style, and value without moving. Explore our project portfolio to see how we’ve assisted clients in integrating stormwater solutions into their home additions.
Cost Considerations
Investing in stormwater management is crucial. Estimated materials costs for various solutions are:
- Rain Gardens: $3,000 – $5,000
- Permeable Pavers: $20 – $30 per square foot
- Dry Wells: $1,500 – $4,000
- Infiltration Trenches: $2,000 – $6,000
- Rain Barrels: $200 – $500
These investments not only ensure compliance but also enhance property value and environmental stewardship. (Labor costs may be additional and will vary!)
Permitting Process
Securing the necessary permits involves:
- Consulting with local township offices to understand specific requirements.
- Developing a comprehensive stormwater management plan.
- Submitting applications and plans for review.
- Implementing approved stormwater solutions during construction.
- Scheduling inspections to ensure compliance.
Our experienced team at Merman Construction can guide you through each step, ensuring a smooth and compliant building process.
Conclusion
Understanding and implementing effective stormwater management is essential when planning a home addition in Montgomery or Chester County. By integrating sustainable solutions, you not only comply with local regulations but also contribute to environmental preservation and enhance your property’s value.
Ready to embark on your home addition project with confidence? Contact us today to discuss your vision and how we can assist in bringing it to life while ensuring full compliance with stormwater management requirements.
Email us at info@mermanconstruction.net or call (610) 489-4132 or click the button below to fill out a Request for Consultation.
Stormwater Management FAQs for Home Additions in Montgomery County, PA
Real answers to the questions Montgomery County homeowners ask most before adding on. Rules vary by township, so read carefully for specifics on your area.
Does every home addition require a stormwater management plan?
Not always, but the threshold is lower than most homeowners expect. In Montgomery County, most townships require a stormwater management site plan once your project adds 1,000 square feet or more of new impervious surface in a connected area. Impervious surface includes the addition footprint, any new driveway, patio, or walkway added at the same time.
In Collegeville Borough specifically, projects adding less than 1,000 square feet of net impervious surface and disturbing less than 5,000 square feet of earth are exempt from a formal stormwater plan. But if your addition footprint alone exceeds that threshold, or if you are also expanding the driveway, you will likely need a plan.
The key word is cumulative. Township ordinances track all impervious surface added to your parcel over time, not just what you are adding today. So even a modest addition might push you over the threshold if you already added a patio or shed in a prior project.
What exactly counts as “impervious surface” when townships calculate thresholds?
Any surface that prevents or significantly slows the absorption of rainwater into the ground. That includes:
- The roof of your new addition
- Any expanded or new driveway area (asphalt, concrete, or packed gravel)
- Patios, walkways, and stoops (concrete, brick, or pavers, unless permeable)
- Decks built on concrete footings close to grade can sometimes count, depending on the municipality
- Sheds with concrete floors or paved aprons
Lawn and unpaved landscaping do not count. Neither do decks elevated well above grade that allow rainfall to pass through. Permeable pavers may be counted at a reduced rate in some townships if installed to specification, since water can infiltrate through them.
What are the stormwater rules specific to Collegeville Borough?
Collegeville Borough operates under Chapter 580 of its municipal code. The key thresholds under the 2023 ordinance are:
- Under 1,000 sq ft added + under 5,000 sq ft disturbed: Exempt from a formal stormwater plan, but erosion and sedimentation controls are still required.
- 1,000 to 2,000 sq ft of new impervious surface: A stormwater plan is required. You may use the Simplified Method for calculations.
- Over 2,000 sq ft of new impervious surface: A full stormwater plan using the Design Storm Method is required, which involves detailed site-specific hydrology modeling.
The Design Storm Method requires that stormwater facilities capture at least the first two inches of runoff from new impervious surfaces, and that at least one inch of that runoff is permanently removed from surface flow through infiltration, reuse, or evapotranspiration.
Questions? Collegeville Borough can be reached at (610) 489-9208. Permit applications including additions are available at the Borough’s permit page.
How do stormwater rules differ across Montgomery County townships?
Every municipality in Pennsylvania must comply with state Act 167 and the federal MS4 (Municipal Separate Storm Sewer System) program, but each township writes its own ordinance. The thresholds, fees, and required plan types vary. A few local examples:
- Montgomery Township: For residential projects adding more than 1,000 but less than 5,000 sq ft of impervious surface, you may pay a fee-in-lieu of building stormwater facilities. As of the 2024 fee schedule, that rate is $1.50 per square foot of new impervious surface.
- Lower Providence Township: Requires a full stormwater management site plan for regulated activities, including a soil study by a licensed soil scientist and infiltration calculations based on NRCS soil survey data.
- Upper Providence Township: Mandates stormwater plans for projects that add impervious surfaces. Check their permit portal for current thresholds.
- Whitpain Township (Blue Bell): Enforces stormwater controls through its engineering department, with project-specific thresholds.
The bottom line: do not assume what applies in one township applies in the next. We handle permit research as part of every addition project, so you will know exactly what is required before we break ground.
What is a rain garden and will my township accept it as a stormwater solution?
A rain garden is a shallow, planted depression in your yard, typically 6 to 12 inches deep, filled with a mix of sand, compost, and native plants. Roof downspouts or drainage pipes direct runoff into it. The water infiltrates slowly into the soil rather than running off the property.
Rain gardens are widely accepted as a Best Management Practice (BMP) by PA DEP and most Montgomery County townships. They are specifically listed in the Pennsylvania Stormwater BMP Manual (Publication 363-0300-002), which most local ordinances in Montgomery County reference directly.
To count toward your stormwater plan, a rain garden must be sized correctly based on the area draining into it and your soil’s measured infiltration rate. Native plantings are preferred because their deep root systems improve infiltration. Common plants for this region include switchgrass, cardinal flower, native ferns, and black-eyed Susan.
A properly designed rain garden typically costs $3,000 to $5,000 for materials. Installation and grading add to that. In many cases, a rain garden sized for a typical room addition can be installed for a total installed cost in the $5,000 to $8,000 range, depending on site access and plant selection.
Will stormwater requirements add significant cost to my home addition project?
It depends on the size of your addition and your municipality’s rules, but for most single-story room additions, stormwater costs are manageable when planned early. Here are realistic cost ranges for common solutions (materials only; labor additional):
- Rain garden: $3,000 to $5,000
- Dry well: $1,500 to $4,000
- Infiltration trench: $2,000 to $6,000
- Permeable pavers (in place of standard concrete or asphalt): $20 to $30 per square foot
- Rain barrels (for minor runoff): $200 to $500
In Montgomery Township, smaller projects (1,000 to 5,000 sq ft added impervious surface) have the option to pay a fee-in-lieu of installing facilities, set at $1.50 per square foot. For a 1,200 sq ft addition, that would be $1,800. This can be a simpler path for projects where installing physical infrastructure is impractical.
The bigger cost risk is discovering stormwater requirements late in the design process, when your plans have already been drawn and submitted. We always review stormwater requirements during the pre-design phase so there are no surprises.