Alternatives Considered but Dismissed from Further Analysis. An alternate site for the detention basin was identified just north of the subdivisions at the south end of the Reserve, having a volume of 63.2 acre-feet and covering 13.5 acres when inundated. This option was rejected due to strong opposition from residents of the subdivisions because it would obstruct views of Snow Canyon and surrounding cliffs, thereby lowering property values. City of Xxxxx Detention Basin Project 21 Environmental Assessment • Constructing a smaller, deeper detention basin on the parcel of land owned by Ivins City was considered but dismissed due to the difficulties and cost of removing water (a longer outlet pipe would be needed that would reduce flows), and maintaining the basin depth, as well as soil and vegetation disturbance that would occur in the wash. • A final alternative considered was to construct new, larger culverts at existing crossings and to not build any detention dams. This alternative was rejected due to insufficiency of new culverts alone in controlling a 100-year storm event without control of the volume and velocity of storm water. Culvert replacements would likely be necessary in other downstream areas under this alternative. City of Xxxxx Detention Basin Project 22 Environmental Assessment
