Stormwater Management for Homeowners

Brian Oram, Licensed Professional Geologist

How to optimize your home and landscape runoff with Rain Barrels, a Clean Gutter System, Swales and more.

About ten years ago, in 2011, I did my first Rain Barrel Workshop. At this workshop, we discussed using low-impact development in new development and changing how stormwater management systems are sized, managed, and maintained from a regional perspective. We then made and customized Rain Barrels using recycled containers.

Most recently, on April 26, 2022, I presented a workshop to Carbon County, Pennsylvania residents through the Carbon County Environmental Education Center. (See presentation) This discussion focused on the individual homeowner's effort to "Get Back to Zero." "Get Back to Zero" means achieving no-change in your home's pre-development and post-development amount of runoff.

Since Carbon County is a rural area, most rural lots are over one acre and either forested or meadow in nature. However, many urban areas have large impervious areas with little green space due to their history as old mining towns.   

This blog post is our effort to develop a guide with respect to runoff for the average rural homeowner and to provide resources for urban citizens and for those who may be looking at rainwater harvesting systems. We'll use Pennsylvania as our case study. 

Pennsylvania Rainfall Perspective:

- 1% of the annual rainfall is 114,500 gallons per acre per year in Pennsylvania.

- A 1000 square foot  home generates approximately 26,182 gallons per year of runoff, excluding the driveway.

- Simpler Terms: 1 inch of rainfall on a 1000 square foot roof is over 600 gallons of water per rain event. Assuming a rain barrel has a volume of 80 gallons, this would require about 8 rain barrels for each 1 inch rain event, but if the barrels are 50 gallons you would need 12 rain barrels (So rain barrels may not be the single solution in all cases).

- Pennsylvania receives about 42 inches of rainfall per year.

- In forested areas, the annual portion of the streamflow that is groundwater is over 60%. This explains why the stream is cold and has water when it does not rain.

- About 80% of Pennsylvanian rain events are less than 1 inch.

How will Climate Change impact Pennsylvania in the future? – likely, Pennsylvania will get more rainfall per year, but less in the summer months and more in the fall and spring. (Recommended reading on "Climate Change" at the bottom of the page)

What if we could turn back the clock?

If we could turn back the clock and modify the initial development to provide a two-story home rather than a one-story home, use a smaller driveway footprint, add some rain barrels, and use a more native landscape approach to vegetation and lawn, the annual rate of runoff would be 18% of the annual flow, which is only a 280% increase.  

If the project added overland flow with biofiltration areas, i.e., part of your lawn stays wet longer and bioretention structures, we are at a 6% annual flow, which is only a 40% increase in the annual runoff. In the presentation example, getting back to zero required the reuse of this water for flushing toilets and then recharging the water through the use of septic systems and installing a "green roof" system to store and evapotranspiration the remaining water. 

Since getting back to zero for an existing home by remodeling and retrofitting does not make financial sense and would likely be very difficult to implement, it may make sense with respect to Urban Stormwater Redesign. We can take some basic steps to reduce our "Stormwater Footprint."

Recommended Steps for Homeowners

The KnowYourH20 team advocates that you "Get Informed" before developing and implementing an action plan in order to have the most effective and cost effective solution. 

Step 1 - Observe and Examine 

Go outside during a heavy rainstorm and observe where and how water enters and leaves your property. Where are the ins and outs, and what is occurring?   

Aside: When I did this, I discovered that a lot of water came from an up-gradient homeowner on one side of my home. I had several downspouts that were clogged and overflowing. My sump pump would turn on nearly immediately, and most of the water ran down the edge of my driveway, along my foundation, and water went from my roof to my foundation drains. No wonder I had a very wet basement and occasional basement flooding. I did not know, and I am a hydrogeologist! (A scientist that studies the Earth with expertise in water and hydrology – flowing water and groundwater).

Step 2 - Start with the Basics

Fix obvious problems and then make additional observations. 

From your observations, what are your problems, and how or where are they interconnected, such as downspouts to foundation drains and a wet or damp basement.

1. Clean and fix the gutters and determine if an area of the home needs a gutter. Add gutter guards or other structures to prevent debris from entering the gutters.

2. Disconnect the gutters to foundational drains and redirect to landscape areas to reduce concentrated flows to spread the water.

3. For concentrated flows onto the property, you may want to consider installing a surface swale that can be filled with rock that can be used as a walkway and hardscape feature. It may appear as a small stream during a rain event that diverts the water to an infiltration area, bioretention structure, water feature, or something that works for your setting.

4. Sketch your property for an overview and study your options.

Step 3: Get Informed

Online Education

Here are some online resources to learn more about stormwater management. (Courses can be used for continuing education as well as credits for professionals)

Using Vegetative Swales, Filter Strips, Bioswales – Biofilters: A Natural Approach to Stormwater Management 

Green Urban Design

Green Landscape Design: Water Conservation

High Performance Landscapes

Educational PDFS

Northwestern Pennsylvania Homeowner's Guide to Stormwater Management

Philadelphia Stormwater Management Guide- Homeowners

New Hampshire Homeowners Guide to Stormwater Management – DIY

Stormwater Management – Your Backyard

Step 4: Make a Plan

Consider the relatively inexpensive things first such as: 

1. Reducing the amount of "European Lawn" 

2. Adding rain barrels 

3. Disconnecting downspouts 

4. Clean gutters

5. Repair and stabilize areas of the property that are eroded

6. Redirect runoff to green spaces

7. Use stormwater for landscape irrigation

8. Review your options (rain garden, tree planting, native grasses, convert impervious areas to porous areas), cistern, and other landscape and gardening features

9. And do not forget about the hidden gem - avoid adding pavement when it is not needed.


Educational PDFS

How to Make a Plan- Homeowners Guide to Stormwater" for Pennsylvania

Pennsylvania Homeowners Guide to Stormwater

Rain Barrel Installation Instructions (Rutgers Cooperative Extension)

Build Your Own Rain Barrel (Chesapeake Bay Foundation)

Roof Top ReDirection

Using Grass Swales

If your plan includes rainwater harvesting for agricultural, animal, or human uses, rooftop rainwater harvesting has become increasingly popular to provide off-grid high-quality drinking water. Rainwater can also be used for gardening, livestock, irrigation, etc. The most common materials used to capture and store rainwater are tile, metal sheets, and plastics. Before using the water, we recommend that the system be flushed, and the water tested.

Test your water with TapScore Advance Rainwater Test

Step 5: Implement Your Plan – Act (Make sure to Maintain and Reevaluate)

After your plan has been implemented, in part or full, go back and reevaluate how it is working. 

It took me over four years to fully implement my plan, which includes:  

Year 1 - Rain barrels 

Year 2 - Implementing surface swales and a small water feature

Year 3 - Disconnecting downspouts and redirecting to landscape features, including native grasses and fruit trees

Year 4 - Added a larger water feature with surface gravel swales that act like walkways.   

More Resources

Rainwater Harvesting: Guidance for Homeowners (North Carolina Cooperative Extension)

Rainwater Harvesting 101: Identifying a Well-Designed Rainwater Harvesting System

American Rainwater Catchment Systems Association (ARCSA) - Rainwater Harvesting 101: Maintaining a Rainwater Harvesting System

Choosing a Pump for Rainwater Harvesting

Rainwater Harvesting: Guidance for Homeowners

Rain Garden

Riparian Buffers

Rain Barrel Products

Rain Barrel Conversion Kit

Rain Barrel Diverter (Oatey) 2"*3" Residential Downspouts

Rain Barrels Diverter with Built-in Filter

Rain Barrel (50 gallons)

Rain Gardens: Sustainable Landscaping for a Beautiful Yard and a Healthy World

Climate Change

What Climate Science Tells Us, What It Doesn't, and Why It Matters