Terrace outlets may be classified as blocked (all water infiltrates in the terrace channel), permanently vegetated (grassed waterway
or a vegetated area), or piped (water is removed through subsurface pipe drains).
. A grassed waterway
is a shallow, sodded, wide ditch that runs down a slope (figure 18-20).
Serious consideration was given to establishing a permanent grassed waterway
along the drainage channel of this field.
ASABE EP464 DEC2006, Grassed Waterway
for Runoff Control.
The validated WEPP Windows model input parameter sets for the four watersheds were then modified to represent a couple of non-structural BMPs such as grassed waterway
and field border in the following ways: 1) a 5 m (16.4 ft) wide field border at the downhill end of a hillslope before entering the channel (on-site BMP); 2) a grassed waterway
with various width depending on the original channel width in the channel area of each watershed (off-site BMP); or 3) a combination of the two.
The p-value was greater than 0.05 for the grassed waterway
and the parallel terrace, indicating that the experts and raters using the evaluation tool did not differ significantly (p<0.05).
This area is in the northern half of what is referred locally as the "potato belt." The drainage basin containing the variable grade diversion terraces and grassed waterway
The least we can do now to prevent our cities from becoming unbearable hot furnaces is to preserve whatever parks and recreation areas are left and to embark on a massive greening program that includes urban forestry, creating rooftop gardens, green architecture, urban agriculture, use of light colored paints, and grassed waterways
, among others.
Examples include power takeoff (PTO) shafts, grassed waterways
, and hydraulic drop structures.