Green roof shown in foreground surrounded by tall skyscapers in urban setting.

Engineering Vegetated Roofs to Optimize Stormwater Management

Live Webinars. Register, free:

Feb 4, 2021 1:00 PM

Feb 18, 2021 1:00 PM

 

 

Urban centers have high concentrations of impervious areas which pose a challenge in managing large volumes of stormwater. Heavy rain events or back-to-back storms cause problems like flooding, property damage, and combined overflow sewer discharge. Green infrastructure, such as vegetated roofs, can help mitigate these problems because they restore the hydrologic cycle in urbanized areas. Vegetated roof systems designed for maximum stormwater management decrease the volume of stormwater within the urban core and reliably delay travel time of stormwater to the treatment plant. These retention and detention strategies help alleviate the burden of heavy stormwater on our cities’ infrastructure. Space is limited.  See learning objectives below.

 

REVIEWS

“Great opportunity and a pleasure.”Thanks to the speakers for their invaluable knowledge.” Francisca Tapia Jr Sustainability Consultant, ABUD

“Excellent seminar” Dan DiMucci, Pennoni Sr. Consultant, RLA 

“Exceptional resources for integrating green roof design with storm water management strategies.  Interactive….a lot of valuable design information.” Meg Needlerd Aeck Sargent, AIA Atlanta

“The presentation was highly informative, and I personally learned a lot. I found the design tools particularly helpful.” Ganesh Nayak, President, Metier Consulting

 

1 LACES PDH

Webinar Learning Objectives

1. The distinction between stormwater retention and detention
2. The importance of detention in urban centers
3. Existing roof top technologies
4. Using biomimicry to re-engineer vegetated roofing system
5. Collaboration: Landscape Architects, Architects, Civil Engineers

Presenters

Sasha Aguilera, GRP, B.Arch, Design Ambassador & Rodney Chaney, BA, GRP, Technical Sales Manager

Sasha Aguilera - Green Roof Consultant

Rodney Chaney

 

 

 

 

 

 

 

Ready to Start Your Next Green Roof Design? Contact us!

With proper planning any rooftop – whether industrial, commercial or residential – can be transformed into a useful, green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to transform your roof. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urbanscape Detention logo by Knauf Insulation

The image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof partner, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Testing, Monitoring and Research by Green Roof Diagnostics

Unbiased, scientific research for the green infrastructure industry.

Installing Green Roofs at 20 Degrees

Construction schedule and handoff deadlines sometimes push green roofs towards seasonal freezeouts.

Many think of winter as the last time of year you would choose to install a green roof. However, with the proper planning, this season of hibernation and dormancy can yield a great result in spring.

 

 

 

December Installation Case Study

Due to the construction schedules, both green roof sections were installed in December, a year apart. While the first phase saw milder winter days of the mid 40’s, the second phase saw mornings starting in the teens and topping out in the mid 30’s.

Project: Arcade Sunshine Condominiums, Washington, DC

Green Roof System: Extensive StormCap Green Roof

Size: 20,000 sf

Phase 1 installation: Oct-Dec 2018

Phase 2 installation: December 17-20 2019

T’was the week before Christmas 2019 …Stormwater Capture Co provided material and install assistance for Phase 2 of a 20,000 sf green roof on an adapted textile mill and new construction structures. These buildings now house new condos in Columbia Heights, Washington, DC.

Benefits of Winter Installation

Green roofs installed in mild winter can benefit from the seasonal timing. Like perennial plants on the ground, all green roofs experience cycles of growth, flowering, and dormancy. During the summer, the plants spend their energy flowering. In autumn, plants divert more energy to root establishment and the sedum plants begin their process of dormancy and energy conservation to ensure their long-term survival.

While fall, spring or an early mild summer can be great times to install a green roof, winter installs will be equally successful as long as some key factors are considered.

Tips for long term performance

      • Keep an eye on the daily and weekly weather forecast. An 18 degree dawn staging can yield above freezing temps by mid-morning.  For example, Phase 2 of the Arcade Sunshine saw average morning temperatures of 18 degrees fahrenheit at 6 a.m. then heated up to around 38 degrees fahrenheit by noon.
      • Base layers can be installed as long as they are pliable. For drainage layers, filter fabrics and retention layers, these components need to be kept dry to keep from freezing on the roll. If saturated, they will not thaw easily. However, if there is enough radiant heat from sunlight, these components can shed some superficial moisture and frost by laying them in the sun.
      • As some of these components are dark they will absorb heat which can make them easier to unroll and will evaporate some morning frost.
      • Growing media can be provided in bulk or in super sack (1.5cy landscape totes). If the media is kept in large hoppers or piles, its mass can keep everything but the outer layer from freezing solid well into below freezing temperatures. If broken down into smaller sacks it is important to move this media quickly so it can be installed. If sacks are frozen solid, it is very difficult for install crews to work and grade this material. If you have radiant heat from a cold but sunny day, this can help loosen the media further on the roof to allow for grading and planting.

Sedum Mats Pre-Grown Outdoors Acclimatize Best

      • Use sedum mats pre-grown outdoors in similar climate as they will acclimatize best. On the east coast, mat harvesters will likely close down after new year through March as the ground seizes up making harvest impossible. Coordinate with us and we can coordinate material and schedule for harvest (and possible short term cool storage) until site conditions and delivery make sense.
      • Pre-cultivated mats should have a minimum of 80 per cent coverage upon installation and should be grown on the farm for 12-18 months to insure a healthy root base and reduce the possibility of erosion of growing media.
      • Ensure vegetation is established upon installation; avoid cuttings or installing plugs in frozen media. During this time of year it’s not worth the time and effort as many cuttings or plugs will dry out completely reducing coverage drastically.
      • If cutting or plugs are used then planting should wait until spring. Base layers and media can still be installed if the conditions allow. A protection fleece should be installed and secured to make sure weed seed banks or wind scour of media is kept to a minimum.

Long Term Survival

              • Diverse species and sedum selection will better ensure probability of long term survival. There are many drought and cold tolerant species to work with. Many are included in our standard mat options. We can work with you to provide the best plug or mat options for your specific roof, climate, and design intent.

Foot Traffic and Irrigation

              • Keep foot traffic over frost-covered plants to a minimum as this will rupture the cellular structure of dormant plants making them subject to die off and disease.
              • As plants wake out of dormancy in spring temporary irrigation is important to promote growth. This is usually started in mid-March or April depending on climate. It is important not to overwater, but to provide enough moisture to get the plants off to a good start.

Contact us with questions or for a quote on green roof systems with installation and maintenance assistance (virtual or on-site).

We hope to have the opportunity to work with you on your upcoming project.

Green roof shown in foreground surrounded by tall skyscapers in urban setting.

To register, click  below:

Dec 17, 2020 1:00 PM

 

 

Engineering Vegetated Roofing Systems to Optimize Stormwater Management

Urban centers have high concentrations of impervious areas which pose a challenge in managing large volumes of stormwater. Heavy rain events or back-to-back storms cause problems like flooding, property damage, and combined overflow sewer discharge. Green infrastructure, such as vegetated roofs, can help mitigate these problems because they restore the hydrologic cycle in urbanized areas. Vegetated roof systems designed for maximum stormwater management decrease the volume of stormwater within the urban core and reliably delay travel time of stormwater to the treatment plant. These retention and detention strategies help alleviate the burden of heavy stormwater on our cities’ infrastructure. Space is limited.  See learning objectives below.

 

REVIEWS

Meg Needle, Senior Associate, Lord Aeck Sargent, AIA Atlanta: “Exceptional resources for integrating green roof design with storm water management strategies. The presentation included ‘soup to nuts’ info. Interactive….a lot of valuable design information.”

Ganesh Nayak, President, Metier Consulting: “The presentation was highly informative, and I personally learned a lot. I found the design tools particularly helpful.”

Webinar Learning Objectives

1. The distinction between stormwater retention and detention
2. The importance of detention in urban centers
3. Existing roof top technologies
4. Using biomimicry to re-engineer vegetated roofing system
5. Collaboration: Landscape Architects, Architects, Civil Engineers

Presenters

Sasha Aguilera, GRP, B.Arch, Design Ambassador & Rodney Chaney, BA, GRP, Technical Sales Manager

Sasha Aguilera - Green Roof Consultant

Rodney Chaney

 

 

 

 

 

 

 

Ready to Start Your Next Green Roof Design? Contact us!

With proper planning any rooftop – whether industrial, commercial or residential – can be transformed into a useful, green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to transform your roof. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urbanscape Detention logo by Knauf Insulation

Purple-Roof SponsorThe image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof sponsor, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Testing, Monitoring and Research by Green Roof Diagnostics

Unbiased, scientific research for the green infrastructure industry.

Join Us for Engineering Vegetated Roofing Systems to Optimize Stormwater Management

REGISTER: Nov 19, 2020 01:00 PM; Space is Limited

Urban centers have high concentrations of impervious areas which pose a challenge in managing large volumes of stormwater. Heavy rain events or back-to-back storms cause problems like flooding, property damage, and combined overflow sewer discharge. Green infrastructure, such as vegetated roofs, can help mitigate these problems because they restore the hydrologic cycle in urbanized areas. Vegetated roof systems designed for maximum stormwater management decrease the volume of stormwater within the urban core and reliably delay travel time of stormwater to the treatment plant. These retention and detention strategies help alleviate the burden of heavy stormwater on our cities’ infrastructure. REGISTRATION IS LIMITED.  See learning objectives below.

 

REVIEWS

Meg Needle, Senior Associate, Lord Aeck Sargent, AIA Atlanta: “Exceptional resources for integrating green roof design with storm water management strategies. The presentation included ‘soup to nuts’ info. Interactive….a lot of valuable design information.”

Ganesh Nayak, President, Metier Consulting: “The presentation was highly informative, and I personally learned a lot. I found the design tools particularly helpful.”

Webinar Learning Objectives
1. The distinction between stormwater retention and detention
2. The importance of detention in urban centers
3. Existing roof top technologies
4. Using biomimicry to re-engineer vegetated roofing system
5. Collaboration: Landscape Architects, Architects, Civil Engineers

Presenters

Sasha Aguilera, GRP, B.Arch, Design Ambassador & Rodney Chaney, BA, GRP, Technical Sales Manager

Sasha Aguilera - Green Roof Consultant

Rodney Chaney

 

 

 

 

 

 

 

Ready to Start Your Next Green Roof Design? Contact us!

With proper planning any rooftop – whether industrial, commercial or residential – can be transformed into a useful, green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to transform your roof. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urbanscape Detention logo by Knauf InsulationPurple-Roof SponsorThe image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof sponsor, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urban Flood Image

Climate Change requires an ideological shift in how we think about infrastructure

Hunter French Illustration from Vice Magazine shows a broken sewer pipe craned

Illustration by Hunter French, Vice Magazine

How does our infrastructure interact with the environment? Our drain pipes, reservoirs, power lines, roads, sewage systems, and more are all designed based on past climate data. But with the climate crisis comes the uncomfortable realization that the past can’t predict what we’ll  get in the future.

Design and Build Adaptable, Flexible Infrastructure

Perhaps, it is necessary to consider more adaptable and flexible versions of infrastructure, such as green infrastructure, to meet our modern challenges.

Below is an interesting article that suggests thinking about the consequences right at the beginning of the design process. Engineers and city planners can work to help avoid the failures.

Read full article, Our Infrastructure is Being Built for a Climate that’s Already Gone, by Shayla Love.

Learn about engineering vegetated roofing systems to optimize stormwater management at upcoming webinar. Click here for more info and to register.

 

Ready to implement Green Infrastructure?  Design a Green Roof! Contact us!

With proper planning any rooftop – whether industrial, commercial or residential – can be transformed into a stormwater management tool and useful green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to transform your roof. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urbanscape Detention logo by Knauf InsulationPurple-Roof PartnerThe image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof partner, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Stormwater Capture Co presents webinar for Eastern US landscape architects

Engineering Vegetated Roofing Systems to Optimize Stormwater Management
Urban centers have high concentrations of impervious areas which pose a challenge in managing large volumes of stormwater. Heavy rain events or back-to-back storms cause problems like flooding, property damage, and combined overflow sewer discharge. Green infrastructure, such as vegetated roofs, can help mitigate these problems because they restore the hydrologic cycle in urbanized areas. Vegetated roof systems designed for maximum stormwater management decrease the volume of stormwater within the urban core and reliably delay travel time of stormwater to the treatment plant. These retention and detention strategies help alleviate the burden of heavy stormwater on our cities’ infrastructure. REGISTRATION IS LIMITED.

Webinar Learning Objectives
1. The distinction between stormwater retention and detention
2. The importance of detention in urban centres
3. Existing roof top technologies
4. Using biomimicry to re-engineer vegetated roofing system
5. Collaboration: Landscape Architects, Architects, Civil Engineers

Register here

Oct 28, 2020 01:00 PM; Space is Limited

Presenters

Sasha Aguilera, GRP, B.Arch, Design Ambassador & Rodney Chaney, BA, GRP, Technical Sales Manager

Sasha Aguilera - Green Roof Consultant

Rodney Chaney

 

 

 

 

 

 

 

Ready to Start Your Next Green Roof Design? Contact us!

With proper planning any rooftop – whether industrial, commercial or residential – can be transformed into a useful, green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to transform your roof. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urbanscape Detention logo by Knauf InsulationPurple-Roof SponsorThe image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof sponsor, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Maintenance Worker on Green Roof in Fall 1

Covid-19 Pushes Construction Deadlines

In early Spring, Covid-19 uncertainty and jobsite safety precautions wreaked havoc on tight construction timelines and Gannt charts across the United States.  For many, deadlines were pushed back.  The anticipated late spring plantings turned into early fall installations.  Ultimately, the Covid delay brings welcome benefits as autumn is an ideal season for plant installation.

Finally Complete with Lush Green Roof

As a stormwater management tool, green roofs are one of the first systems calculated at the design stage by civil engineers.  After years of planning and construction, they are one of the last building features completed.  Now, finally, lush, living green roofs top the finished buildings helping manage stormwater as well as provide other benefits.  To the relief of all involved – designer, supplier, installation contractor and building owner – the planting of a green roof marks the final chapters to construction.

Benefits of Autumn or Winter Install

What some don’t know, is that green roofs installed in autumn or mild winter can benefit from the seasonal timing. Like perennial plants on the ground, all green roofs experience cycles of growth, flowering, and dormancy. During the summer, the plants would be spending their energy flowering.  In autumn, the sedum plants begin their process of dormancy and energy conservation. To ensure their long-term survival they take advantage of the cooler moist temperatures and divert energy to establish roots in their new home on the rooftop.

Tips for winter survival and long term performance

  • Pre-cultivated mats should have a minimum of 80 per cent coverage upon installation to reduce the possibility of erosion of growing media
  • Ensure vegetation is established upon installation; avoid cuttings
  • Use sedum mats pre-grown outdoors in similar climate as they will acclimatize best
  • Diverse species and sedum selection will ensure probability of long term survival
  • Keep the green roof hydrated in the autumn months
  • Avoid foot traffic over frost-covered plants

Close up of drain surround by paver on green roof

Next, Maintenance Planning

Now it’s time to change gears from loading, grading, and planting to long term planning.  A maintenance plan is required to keep this rooftop stormwater management tool performing. As with all building systems, nothing is truly maintenance-free. Every component requires periodic maintenance to perform according to the requirements set out during design.

Routine maintenance needs to start near the inception of the project and be carried through to building handover and beyond. A maintenance checklist will include drain inspection and more.  Read this blog on fall maintenance.

Ready to Start Your Next Green Roof Design? Contact us!

With proper planning any rooftop –  industrial, commercial or residential – can be transformed into a useful, green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to transform your roof. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urbanscape Detention logo by Knauf InsulationPurple-Roof PartnerThe image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof partner, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool.

Have a Clear Maintenance Plan

The change in seasons and arrival of Autumn requires building maintenance before winter falls. This includes landscapes around and on top of our buildings – green roofs.

The beautiful, living roofs that dot our urban landscape also require care. Some municipalities call for rooftop maintenance such as Washington, DC which requires rooftop inspections twice a year. Furthermore, many warranties are tied to performing maintenance and filing reports. Ultimately, maintenance keeps your green roof performing as it should.

Maintenance requirements can vary slightly with different designs and plant materials. Each assembly should have a clear maintenance plan.

 

Grasshopper on a dormant green roof

Fall Maintenance Checklist

  • Fall weeding
  • Clean up garbage and matted tree leaves
  • Drain inspection
  • Infill with plugs and mats, as needed
  • Temp or permanent irrigation line blowout (to avoid freezing)
  • Plot your spring game plan, make note of materials or action for following visit

The extent of maintenance above depends on the design, the plant selection, the depth of growing medium, the roof’s exposure and the weather. While it is hard to predict the weather, a designer can opt for a system with low maintenance features to reduce overall labor and cost.  Read more on how to design a low maintenance green roof, here.

 

 

 

Ready to Start Your Next Green Roof Design? Contact us!

With proper planning any rooftop – whether industrial, commercial or residential – can be transformed into a useful, green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to transform your roof. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urbanscape Detention logo by Knauf InsulationPurple-Roof PartnerThe image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof partner, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool.

StormCap Pre Vegetated Roof System layers shown in a 3 dimensional build up.

Typical lightweight, low maintenance StormCap™ system profile.

Design with Maintenance in Mind

Top Four Design Considerations

 

1. Safe Access

Easy access and safety considerations make for quicker maintenance.

 

2. Lightweight System

Lightweight systems such as StormCap™ achieve desired stormwater management goals and are easy to install and typically require lower maintenance. A thin-layered system with a dense vegetated mat over 2-4″ engineered growing medium tends to be less inviting for harmful weeds and therefore require less routine, manual weeding.

 

3. Plant Selection
Hardy and drought tolerant sedum plants grown outdoors are ideal. Sedum are more resistant to stress and extreme temperatures.  Sedum mats can be successfully installed in autumn or winter months. Maintenance personnel should be familiar with the green roof plants and the owner’s green roof aesthetic preference as some “weeds” might be tolerated in addition to the plant selection.

Irrigation bib hose next to mechanical units on green roof.

Irrigation bib on green roof.

 

 

4. Irrigation
Access to water, with adequate pressure, close by the rooftop is critical for supplemental irrigation in the establishment phase and during periods of drought.

 

 

 

Ready to Start Your Next Green Roof Design or Install? Contact us!

With proper planning any rooftop – whether industrial, commercial or residential – can be transformed into a useful, green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to transform your roof. Email or call (855) 786-7626 for stormwater calculations specific to your project.

Urbanscape Detention logo by Knauf InsulationPurple-Roof PartnerThe image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof partner, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool.

Project Info

Designer: DRA Architects, Inc.

Landscape Architect: Warner Larson, Inc

Installer: The Waterproofing Company

Vegetated Roof at Cape Cod Tech Manages Stormwater and Teaches Sustainability

The highly visible 25,000 square foot green roof comprised of the innovative StormCap™ green roof system offers numerous benefits to the newly constructed Cape Cod Tech High School, as well as the local watershed.   It is fitting that the region’s leader in technological education is also a study in building sustainability and innovation.

North view of the Cape Cod Technical Regional High School green roof shows contrasting sections of Marroon and Standard pre-grown sedum mat mixes.

Newly Installed Vegetated Roof Thrives

One month after installation, the newly installed vegetated roof had acclimated beautifully to the location. The photo on the left was taken weeks after the April 2020 installation under strict Covid-19 safety procedures. (See video below.)

Aesthetically Pleasing and Distinct Design

Among its design features, is a highly aesthetic 25,000 square foot green roof that consists of contrasting sections of Marroon and Standard pre-grown sedum mat mixes. Various species of flowers and foliage change color and height with the seasons and require minimal fertilization and maintenance year round.

 

 

Green Roof Tackles 2.54″ Rainstorm

The StormCap™ 2.5+1 green roof system can handle a 2.54″ rainstorm. As a result, this helps reduce localized flooding and stormwater pollution. The lightweight system weighs only 23 lbs/sf saturated, and retains up to 1.59 gal/sf of stormwater. The 4″ profile includes drainage, filter, retention, media and a plant base delivered in pre-grown sedum mat.

Its components include Knauf Insulation’s Urbanscape® needled mineral hydro blanket that uses no binders and has a superior retention of 90% of water by volume.

In addition to the various environmental benefits including energy efficiency and mitigating heat island effect, the highly visible green roof helps further educate students on green infrastructure and climate resilience.

 

Start Your Design

Any rooftop – whether industrial, commercial or residential – can be transformed into a useful, green space. Stormwater Capture Co is a one-stop-shop for green roof systems and technical support.  We supply a range of  systems from lightweight and biodiverse, to detention green roofs.  We have custom green roofs that meet specific stormwater management and biodiversity goals. Contact us to start your green roof transformation.

Urbanscape Detention logo by Knauf InsulationPurple-Roof PartnerThe image conveys this system is powered by the Purple-Roof concept.

As a Purple-Roof partner, Stormwater Capture Co has access to the latest green roof stormwater test data and related innovative hydrologic modeling tool.  Email or call (855) 786-7626 for stormwater calculations specific to your project.