This was a design feature by PFRA engineers to minimize development costs, and to integrate surface drainage with water delivery to the irrigated parcels.
ðɪs wʌzɐ dɪzˈaɪn fˈiːtʃɚ baɪ pˈiːfɹˈɑː ˌɛndʒɪnˈɪɹz tə mˈɪnɪmˌaɪz dɪvˈɛləpmənt kˈɔsts, ænd tʊ ˈɪntᵻɡɹˌeɪt sˈɜːfɪs dɹˈeɪnɪdʒ wɪð wˈɔːɾɚ dᵻlˈɪvɚɹi tə ðɪ ˈɪɹᵻɡˌeɪɾᵻd pˈɑːɹsəlz.