Sentence:  If your pool is located on or near sloping ground , it may have natural drainage which <WSD>is</WSD> certainly more desirable than to be faced with the annual expense and labor of first pumping out the water and then scooping out all the debris . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)