- Provide control rainfall in ponds Remote Impounding Basin, not to exceed two cubic meters or a height of water equal to 8 cm (so that the filling of Remote Impounding Basin) still has a volume of less than 46. API 2510 standard cubic meters as the volume of not less than 50 percent of large tanks) by installing a drain valve between rain. The patio area to the tank Remote Impounding Basin to control the flow of rainwater into the pit Remote Impounding Basin Maximum altitude limit.