Silva Cells at Diehl Park

Beneath the surface of the east parking lot at Diehl Park, Silva Cells aid in stormwater management.

Silva Cells

  • Are modular plastic frames designed to support traffic loads, allowing for a suspended pavement in parking lotsand streets.
  • Prevent soil from getting compacted around tree roots, allowing for large tree growth and on-site stormwater management.
  • Make it possible to grow large canopy, mature trees within the confines of a parking lot.

In addition to helping cool and clean the air and provide beauty to the community, mature trees consume large volumes of water through soil storage, interception and evapotranspiration. A large quantity of planting soil provides ideal conditions for tree growth to occur and also provides storage for additional stormwater.

A large oak tree can transpire 40,000
gallons of water annually. (USGS)

Trees provide an abundance of economic, social and environmental benefits. A city’s tree canopy can significantly reduce stormwater runoff and save millions of dollars in drainage infrastructure needs. A healthy level of urban tree canopy is around 40 percent. The City of Defiance is in the process of creating an inventory of existing street trees and subsequently developing a Master Planting Plan.

This combination of green infrastructure practices means that there is no longer a connection from Diehl Park into the combined sewer system.


This project was financed in part through a grant from the Ohio Environmental Protection Agency under the provisions of the Surface Water Improvement Fund.

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