Convert litres to cubic centimetres, then divide by the base area.<br><br>
&bull; Water volume = 25.272 L = 25272 cm&sup3;<br>
&bull; Base area = 40 × 36 = 1440 cm&sup2;<br>
&bull; Water height = 25272 ÷ 1440 = 17.55 cm<br><br>
Final Answer: 17.55 cm