Tree tops



When rain falls in natural, undeveloped areas, the water is absorbed and filtered by soil and plants. As urban areas grow, less and less of this natural environment remains. Cities typically manage storm water by guiding it into storm drains and sewer systems, which often have limited capacities and require complex and expensive infrastructure. Water runoff in urban areas also often captures litter, heavy metals, oils, bacteria, and other pollutants found on streets and sidewalks.

Green infrastructure captures, absorbs, or diverts storm water from urban areas before it enters sewer systems or causes flooding. Green infrastructure also filters and cleans stormwater naturally, reducing the negative impact before stormwater reaches rivers, lakes, and streams. Green infrastructure creates permeable surfaces and/or retains storm water for slower release into the storm drains over time, allowing storm water to be naturally absorbed where it falls instead of quickly flowing into City sewers. Reducing the amount of stormwater that drains into the City’s combined sewer system is a cost-effective way to control localized flooding and reduce pollution in local waterways like the Hudson and Hackensack Rivers. Green infrastructure can also help to beautify neighborhoods, improve air quality, and reduce the City’s carbon footprint.

Jersey City has installed a few examples at and near City Hall, including the following items:


BioswaleBioswales are oversized tree pits filled with plants, sand, gravel, and engineered soil, which are specifically designed to absorb water. Inlets divert rainwater from the street into the bioswale instead of into the storm drain. They are designed to accommodate larger quantities of water than standard tree pits and can divert runoff from large impervious areas such as sidewalks, parking lots, and streets.

Maintaining Bioswales

  • Regularly remove litter and other debris that enters the bioswale.
  • Ensure openings in the curb allow water to flow freely into and out of the bioswale.
  • Young plants will require frequent watering during the first 12-18 months to ensure proper growth, but will require minimal maintenance after this period.
  • Remove weeds and invasive plants immediately.
  • Inspect the soil and plants during and after rain events to ensure proper filtration and that there is no standing water left after 72 hours.
  • Do not use fertilizer or pesticides in the bioswale.
Rain barrels are containers connected to a roof gutters and downspouts that divert stormwater before it enters sewers. Typical barrels collect as much as 50 gallons of water. You can get one from the Jersey City MUA.

rain gardenRain gardens are an inexpensive and simple way to mitigate urban stormwater runoff. Rain gardens are shallow, constructed depressions that are planted with deep-rooted native plants and grasses. They are strategically located to capture runoff from hard surfaces such as driveways, parking areas, sidewalks or streets. Rain gardens fill with a few inches of water after a storm and then filters into the surrounding soil, rather than running off to the street or burdening the storm drain.

Benefits: The benefits of planting rain gardens are numerous. Rain garden benefits include pollution control, flooding protection, habitat creation and water conservation.

  • Filter runoff pollution
  • Recharge local groundwater
  • Conserve water
  • Improve water quality
  • Protect rivers and streams
  • Remove standing water in your yard
  • Reduce mosquito breeding
  • Increase beneficial insects that eliminate pest insects
  • Reduce potential of home flooding
  • Create habitat for birds & butterflies
  • Survive drought seasons
  • Reduce garden maintenance
  • Enhance sidewalk appeal
  • Increase garden enjoyment



Here is a guide on how to maintain and inspect a rain garden from our partners Rutgers Agricultural Experiment Station and the Water Resources Program.


porous pavementPorous/permeable pavement is a permeable surface that allows stormwater to travel directly into the ground below instead of into storm drains. Porous pavement is commonly found in walkways, parking lots, tree pits, driveways and patios, but some types are not suitable for standard roadways. Porous pavement can be made with concrete, asphalt, or interlocking pavers.


  • Permeable paving surfaces are effective in managing runoff from paved surfaces. Large volumes of urban runoff causes serious erosion and siltation in surface water bodies.
  • Controlling pollutants: permeable paving surfaces keep the pollutants in place in the soil or other material underlying the roadway, and allow water seepage to groundwater recharge while preventing the stream erosion problems. They capture the heavy metals that fall on them, preventing them from washing downstream and accumulating inadvertently in the environment. In the void spaces, naturally occurring micro-organisms digest car oils, leaving little but carbon dioxide and water.
  • Trees: Permeable pavements may give urban trees the rooting space they need to grow to full size. A “structural-soil” pavement base combines structural aggregate with soil; a porous surface admits vital air and water to the rooting zone.


  • Regularly inspect porous pavement for proper filtration, specifically looking for materials that might be limiting water permeability (such as dirt, sand, gravel).
  • Do not use sand and salt on the surface during cold temperatures, and use caution with plows, shovels, and other snow scrapers as permeable surfaces are not as smooth and flat and can be damaged during snow removal.