Inserted on the bottom of the assembled Flo-Well Dry Well Side Panels, the bottom panel prevents soil erosion under the dry well and provides a solid, stable base when adding a pump into the tank to send collected water to another location. No gravel is needed beneath the Flo-Well Dry Well Tank when using the bottom panel. Works in all soil conditions. The Flo-Well Dry Well System is used to detain and slowly release collected stormwater runoff. With the Bottom Panel, it can also work as a reservoir. Flo-Well Dry Wells can be stacked for additional capacity. Secure a bottom panel on the lowest Flo-Well tank to prevent erosion of the soil beneath the entire system. For local areas that require stormwater detention and infiltration on property, the Flo-Well Dry Well System is an accepted product, either installed by itself or as part of a larger integrated set-up. It's also an effective drainage solution as an integral component of rain gardens and bioswales, to manage the flow and absorption of runoff from impervious surfaces. Use the free Flo-Well drainage calculator on NDSpro.com/flo-well-calculator to configure the right sized system for your specific drainage problem. The preferred choice of contractors, NDS is dedicated to helping you with the products, tools, and support you need to get the job done right the first time. Color: Black/Matte.