Question

Shallow and broad sloping channels, with vegetation to channelize water flow and allow ground water recharge are called

• A. Gutters
• B. Ha-ha
• C. Swales
• D. Catch basins

Hint:

Landscape Engineering Guideline: Whenever you see a question about "shallow, broad, vegetated landscape depressions designed to slow down rainwater and filter it back into the earth," think of Swales. They serve as nature's green drainage channels.

Answer 1

The Correct Option is C

Concept: Sustainable Urban Drainage Systems (SuDS) and ecological landscape design use natural, vegetative features to manage rainwater runoff. Instead of routing stormwater through concrete pipes, eco-friendly infrastructure seeks to slow down, spread out, and filter rainwater naturally to promote groundwater infiltration.

Step 1: Defining the technical attributes of a Swale.
A swale (or bioswale) is a shallow, wide landscape depression with gently sloping sides that is planted with dense, water-tolerant vegetation. It performs three vital hydrological functions:
• Conveyance: It guides surface runoff away from critical infrastructure along a gentle slope.
• Infiltration: The broad, unlined dirt base slows water flow, allowing it to percolate downward and recharge underlying aquifers.
• Water Treatment: As water moves through the vegetation and root networks, suspended solids, heavy metals, and urban pollutants are naturally filtered out.

Step 2: Evaluating the alternate drainage and landscape elements.
Let us review why the other choices are unsuited:
• Gutters: Narrow, hard-surfaced (often metal, plastic, or concrete) channels attached to roof edges or road curbs designed to rapidly remove water. They do not allow groundwater recharge or incorporate vegetation.
• Ha-ha: A traditional landscape design element consisting of a recessed landscape wall or hidden ditch. Its purpose is to create an invisible vertical barrier for livestock without interrupting panoramic views, serving an aesthetic and containment function rather than stormwater management.
• Catch Basins: Vertical masonry or concrete underground structures fitted with a grate, acting as a sediment trap before water enters a closed subterranean storm sewer pipe network. Thus, swales accurately fit the definition of vegetated, broad sloping channels used for sustainable groundwater recharge.