This is a case of total lack of communication and disregard for personal property and the environment.  The neighbors of our client in Mamaroneck decided to lift the grade of their property but failed to do so in a responsible way. The environmental impacts are serious and not easily remedied.  Green Jay Landscaping was hired to provide an environmental site assessment and mitigation plan.

When Neighbors Go Too Far

The neighbor constructed a fieldstone retaining wall to raise and level the grade for a lawn installation. In the process, they installed subsurface PVC pipes to conduct stormwater away from their property and into a drainage easement on our client’s property. The easement leads directly to a stream – an unregulated wetland, but a valuable freshwater way nonetheless. The neighbor also removed significant vegetation including a mature 22” in diameter Maple.  Other understory vegetation including native shrubs, perennials and ground cover were carelessly removed and the area was blanketed in geo-textile fabric followed by non-composted wood chips at depth of 1-2.5’. 

Impacts of Environmental Disruption

After visiting the site, conducting field observations & analysis, we prepared a list of impacts of the landscaping conducted by the neighbor. 

  1. By installing a lawn, the neighbor increased semi-impervious surface area, thereby increasing sheet flow volume. Discharging both subsurface water and sheet flow towards our client’s property altered the natural hydrology leading to saturation of the ground and destabilization of the nearby large trees. 
  2. The increased volume of stormwater will continue to impact permanently as there is inadequate outflow downstream. Soil conditions are expected to remain wetter than the previous conditions. Potential erosion and flooding will likely continue into the foreseeable future. 
  3. Any and all contaminates from the stormwater runoff including VOC’s, inorganic compounds, fertilizers etc. will be deposited and carried by stream. Water quality may be compromised.
  4. Complete and total vegetated buffer removal results in further alteration of hydrologic impact on our client’s property including exposure to more severe wind storms, erosion and flooding as well as inability to provide usable yard space. Mold spores are likely to proliferate as evidenced by mushroom colonization at ground level, creating possible respiratory stress in the backyard environment.
  5. Most indigenous, native, ecologically beneficial existing plants and soils were buried by woodchips or completely removed in the case of the 22” Maple. This vegetation had provided valuable habitat for countless species as well as ecosystem services including air purification, emission secretions, and stormwater uptake. 
  6. The raw, uncomposted woodchips installed in place of the vegetaion which will alter the soil chemistry and biology by leaching nitrogen into soil and stream. This further potentially impacts water quality. 
  7. The construction of the fieldstone retaining wall further impedes the natural sheet flow drainage and decomposition process of wood chips, increasing mold proliferation. This deep layer of slowly decomposing wood chips are unstable and do not provide a media for new planting to grow, survive and thrive.
  8. The overall effect is sterilized soil and suppression of natural respiration of the remaining trees (by covering and saturating their root system) while prohibiting natural processes of regeneration and restoration. 
  9. The woven geotextile fabric was installed intentionally before the woodchips were deposited, further inhibiting the natural processes as well as making restoration and mitigation unnecessarily complicated and expensive. 

We consider this a rare example of destruction of highly valued upland, mesic and wetland ecological habitat, which we are continually losing due to approved intentional development.

It’s most unfortunate this disastrous result could have been prevented by proper communication between parties. It is unconscionable that respect to the property, the environment and the client/neighbor was not considered before construction and development began.

Proposed Mitigation Solutions 

  1. Cleaning, widening and deepening of stream corridor channel where possible to allow for increased flow and volume. Expanding stream with an overflow holding pool and installing subsurface hydrologic piping to alleviate seasonal flooding.
  2. Removal of 90% of wood chip material is necessary to return to a disturbed but acceptable soil condition, this includes removal of geotechnical fabric, allowing for landscape installation of Restoration and Mitigation Plan
  3. Landscape restoration planting to provide habitat and biomass necessary to improve climate for human health as well as compensate for loss of property value. This riparian buffer would provide ecosystem services to restore the ability to absorb and manage storm water flow during the course of normal storm events.
  4. If the retaining wall is to remain it should be backfilled with engineered soil plus topsoil for planting medium instead of woodchips, thus increasing stability, drainage and allowing for planting and revegetation.
  5. Stream bank wetland planting to stabilize soil erosion improve water quality, appearance and wildlife habitat.

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