[Tex/LaTex] Why won’t the \otoprule command work in table formatting

Question

Primer: I'm very new to LaTeX. I am creating a table with the following code. Here is part of the table:

\usepackage{tabularx, multirow, booktabs}
\begin{table}[tp]
\caption{Rain garden site characteristics}
\label{table:11}
\begin{tabular}{c r @{.} l c r @{.} l r @{.} l r @{.} l r @{.} l}
Site ID &   Surface Area        &   Install Date    &   Roof Catchment Area &   Total Cactchment Area   &   $A_garden$/$A_imper$    &   $A_garden$/$A_total$    \\\otoprule
1   &   10&2    &   2007    &   49&7    &   49&7    &   20&6    &   20&6        \\\midrule
\end{tabular}
\end{table}

I cannot, for the life of me, figure out why it has a problem with \otoprule. I've seen it in many table style guides, and can't figure out what I'm missing. The error code I get is:

! Undefined control sequence.
<recently read> \otoprule
1.5 ... A_imp$ & $A_garden$/$A_total$ \\\otoprule

Thanks for any suggestions!

Answer 1

In the cited source\otoprule is defined as follows:

\newcommand{\otoprule}{\midrule[\heavyrulewidth]}

So you should add the preceeding line to obtain the desired result.