Portland, Oregon is a leader in “green” technology and building methods. “Green” methods of groundwater removal are part of the success of our clean environment. For many years I was a commercial-investment real estate broker. My specialty was selling multi-family and single family residential parcels to developers.
As the years went along, the trend became more focused on stormwater retention ponds for sub-division groundwater runoff, rather than sending roof and groundwater into storm sewers or creeks.
Many projects that we designed used this type of groundwater removal as the groundwater is perked into the ground, rather than sending it into storm sewers. Paved surfaces and concrete driveways reduce the amount of land that is open space and is available to soak up groundwater. Stormwater retention ponds give aesthetics and function, where the land has been compromised by development. This has become the standard now in Portland metro area development for “green” groundwater replacement of our water table.
We love our “green” Oregon, and we intend to make sure it stays that way. Development is going to take place, but the manner in which we treat our groundwater and roof water collection is one of the most important development considerations.
Developers are now given plans that include stormwater retention ponds as conditions of approval for the subdivision. Stormwater retention ponds are seldom elected by the developer as an option these days, they are mandated where they are feasible.
Venting our neighborhood groundwater and roofwater with french drains, specifically hand excavated french drains should be mandated as well, but they are not. They are suggested, but not mandated.
The builder is most likely still venting roofwater into storm sewers where there is no stormwater retention pond. Cities and counties need to start mandating the construction of french drains and drywells in all feasible areas.
Cities should be more accepting of rock filled drywells, rather than concrete cylinder type tanks. Rock filled drywells are more in harmony with nature, and natures ways, without the high cost, and the hazards of collapse and accidents that come with open center concrete cylinder installations.
Homeowners building homes should understand that “green” roofwater and groundwater removal methods should be required for the health of our environment.
It makes more sense from a “green” perspective to split the groundwater distribution into numerous drywell areas where the groundwater can be soaked into the ground rather than channeled to low point drains that run groundwater into creek discharges feeding rivers.