I would recommend that you use at least 3 per foot. You may need more depending on the weight of the rain or snow load you expect it to be able to withstand without ripping off the house.
ditch, channel, drain, dugout, trough, gutter, and/or furrow
In weather terms, a trough refers to an elongated area of low pressure that typically brings unsettled weather conditions such as precipitation, clouds, and cooler temperatures. Troughs are associated with rising air and can lead to weather patterns like rain showers and thunderstorms.
You can use a ladder to get up to them and clean them or there is a wand with a hook on the top shaped like the hook on a hanger that you attach to a garden hose and wash out the gutter.
A trough aloft is generally associated with unstable weather conditions, such as the potential for thunderstorms, heavy rain, and strong winds. This is because a trough aloft represents a region of lower pressure in the upper atmosphere, which can lead to the development of unsettled weather patterns.
An eaves trough is a gutter attached to the edge of a roof to collect and redirect rainwater away from the building's foundation. It helps prevent water damage and erosion by ensuring that water does not pool near the base of the structure. Eaves troughs are commonly made of metal or PVC materials.
December 1 trough May 30th - out of the hurricane season.
Weather Radar are used. A weather radar helps a pilot to find out about the weather conditions while flying and they anticipate any changes in the weather.
A pressure trough is associated with a stationary front. This type of front typically causes prolonged periods of unsettled weather, often resulting in rain or storms, due to the convergence of air masses along the boundary.
Trough
Troughts is not a word but if you mean "trough(s)" then "canal(s)", "channel(s)" , "ditch(s)", "or "gutter(s)" could work.
A very old trough. A hard-wearing trough. A durable trough. One tough trough.
the trough the trough the trough