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
A trough is distinguished on the weather chart by system of isobars which appear sharply curved along a line .this curves are concave towards low pressure. Trough may be termed deep or shallow according to whether the curvature of the isobar is acute or gentle. The weather associated with a trough is generally cloudy with precipitation.
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.
Troughts is not a word but if you mean "trough(s)" then "canal(s)", "channel(s)" , "ditch(s)", "or "gutter(s)" could work.
Trough
A very old trough. A hard-wearing trough. A durable trough. One tough trough.
A scum gutter is a channel or trough designed to collect and divert unwanted debris, foam, or scum that accumulates on the surface of liquids, particularly in industrial processes or wastewater treatment. It helps maintain the efficiency of the system by preventing these contaminants from re-entering the main body of liquid. Scum gutters are commonly used in various applications, including sewage treatment plants, clarifiers, and oil-water separators.