A marsh is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and
features grasses, rushes, reeds, sedges, other herbaceous plants, and moss. A marsh is different from a
swamp, which has a greater proportion of open water surface and may be deeper than a marsh. The freshwater marsh
relies on rainfall for its water. This is in contrast to the saltwater marsh which relies on the tides.
Wait a minute! You are talking about marshes but this EarthCache name is: Colony Farms Swale. All right! Swales are
marshes, moist grasslands, dense shrubs, or damp flats in linear depressions formed between successive ridges as
land mass barriers, islands, capes, or beach plains build seaward. In the case of the A Colony of Swales it is a
bioswale topography where groundwater intersects with the bottom of the swale and saltwater flooding is infrequent.
So... What is a swale? A swale is a low tract of land, especially one that is moist or marshy. The term can refer
to a natural landscape feature or a human-created one. Artificial swales are often designed to manage water runoff,
filter pollutants, and increase rainwater infiltration.
A bioswale is an urban landform used to convey surface water in order to enhance infiltration and reduce surface runoff. Bioswales are typically moderate gradient devices (approximately one to five percent in channel slope) and may be covered by grasses, landscape fabric, mulch or other vegetation or leaf litter. These landforms are typically integrated into an urban landscape design to enhance the visual appearance, but also may be used in agricultural settings as drain ways to intercept runoff containing silt, pesticides or nutrients. In urban settings the bioswale may serve to reduce sediment load and other water pollutants from reaching natural watercourses. A typical bioswale has gently sloping or curved sides to emulate the appearance of a natural watercourse; in fact, if established with appropriate native vegetation, the bioswale may become a riparian corridor or wetland restoration element of the natural landscape
Swales as used in permaculture are designed to slow and capture runoff by spreading it horizontally across the
landscape (along an elevation contour line), facilitating runoff infiltration into the soil. This type of swale is
created by digging a ditch on contour and piling the dirt on the downhill side of the ditch to create a berm. In
arid climates, vegetation (existing or planted) along the swale can benefit from the concentration of runoff. Trees
and shrubs along the swale can provide shade which decreases water evaporation.
In order to log this Earthcache you must go to all of the listed coordinates and email me the answers to the
following questions. At each location you will find information that you will need combined with some basic
interruptive research to answer the questions below as well as some specific details pertaining to the questions.
Please do not post your answers with your log. If you do so it will be deleted.
S1-1. What is the purpose of the Colony Farm Bioswale?
S1-2. How many hectares is the Colony Farm Bioswale (1000sq meters=1 hectare)?
S1-3. What is the elevation difference from the upper parking to here?
Stage 2 Sluice Tide Gate: Go to N 49° 14.199 W 122° 48.036 and Answer the following questions:
S2-1. Where will this filtered water runoff go to next?
S2-2. What is one native plant used in the filtration process?
S2-3. What is the high water marking on the gate?
Stage 3 Seasonal Ponds: Go to N 49° 14.604 W 122° 47.474 and Answer the following questions:
S3-1. As you have been walking around the Swales describe your observation of the channels
and comment on why they were formed that way?
S3-2. Explain the purpose of seasonal ponds
S3-3. Describe the conditions at the marsh ponds. Is the area wet or dry?
As optional additional logging requirements (ALR) post a photo of you and your GPSr in your favorite location. You
are welcome to post additional photos of your visit. Please do not post photos that would give away the answers to
any of the educational portion of this cache (stages 1 and 2 and 3). Logs with photos that provide the required
answers to the questions will be deleted.
Email me the answers to the questions for Stages 1 and 2 and 3