As shown in the image below, a swale has been constructed below a retaining wall, $7\mathrm{.}5$ m away a house. The grade at the side of the house is $126\mathrm{.}42$ m $,$ and the ground slopes away at $2\mathrm{.}1\%$ towards the $0\mathrm{.}23$ m high armor stone retaining wall. The swale is $0\mathrm{.}49$ m away from the retaining wall $($measured horizontally$)$ at a slope of $5$:$1.$ If the swale is $27\mathrm{.}1$ m long at $1\mathrm{.}5\%,$ what is the elevation at the swale outlet?