It was once a given that I would be asked how land without standing water could be considered a wetland. Inevitably, the client would state,” But my shoes aren’t getting wet…” The days of the wet loafer wetland delineation are long gone.
Water, frequently called hydrology, is the second parameter of wetland determination. Water comes to the wetland by any number of sources- streams, overland sheet flow, groundwater, seeps, storm flooding, broken utility pipes and old farmland irrigation tiles. The water is held in place by various restrictions- clay layers, paddock compacted hard-pan, pavement, ledge and elevated bedrock and construction compaction (soil storage sites).
Standing water does not need to be present all year to qualify as a wetland. Actually, it needs to be present little more than 10 days per year and it only needs to be near the surface during that time. Fear not, water tells a story of the travels.
Hydrology, when not directly observed as wet soil or standing water in the sample hole, is frequently observed through other signs. These signs may be elevated tree roots (it looks like the tree is attempting to stand up out of the ground or triangle roots), dark water stains around the base of the trees, dead grasses hanging from plants (it looks like a seaweed line, but in the woods) and scour marks or drainage patterns.
So who defined how much water makes a wetland and how did they agree? Here is where it gets fun. Army Corp of Engineers defines the hydrology at the federal level. This is generally adopted and incorporated into State regulation. In Massachusetts, each Municipality (under their own regulations/Bylaw) can incorporate, change and create a definition of wetland hydrology. Fortunately, most towns are in agreement and utilize the State definition. The Towns that do change the definition, generally do so radically. Believe me, you won’t look at a pavement puddle the same way again.
As always there is an exception.
Vernal or ephemeral pools are another matter entirely. These pools are supposed to dry up. Most do, some don’t. Some hold water in the Spring. Some hold water in the Fall. They don’t have fish, except under a few municipal bylaws that specify the pools don’t have PREDATORY fish. These pools have a special place within the State regs and can greatly affect site design. A State agency determines whether they are certified pools and this dictates State regulatory application. Municipalities frequently include that a pool does not need to be certified to be regulated locally. This will be covered in more detail under wildlife.
At first glance, site hydrology factors can be stressful. It would seem that every time is rains, the land could be called wetland (tick, tick -the 10 day rule) and that any upland dry spot could be a vernal pool. Before you start stocking sump pumps in the construction trailer, know that water isn’t the be all and end all. It is one of the parameters.
Vegetation also tells a tale.
