Eighty five percent of homes in the US experience a flooded basement sooner or later - these are the estimates from home builders and insurance providers.
The sump pump was invented to handle minor basement flooding problems, and this solution came with it's own set of new problems. Questions about safety soon arouse with this machinery open and exposed. Also, small animals could get stuck in the sump pit. Unable to escape it could clog the system, as well as cause an unpleasant mess when it came time to cleanup.
These issues, of course lead to the sump pump cover being made available.
Installing a sump pump cover gives the security and peace of mind that no one can bump, step on, or otherwise damage the unit - leaving your basement unprotected. And no foreign objects will be able to enter the sump pit causing malfunction or inefficiency.
Today, more and more systems are sold with a complete line of accessories, which includes a cover. Other sources of sump pump covers are specialty home stores that sometimes carry these items sold separately from a pump unit.
Now days, it is fairly standard for sump pumps sold in the United States to include covers. If you are outside the United States, or in need of a cover for an older installation, check the specialty home stores near you.
Do not be tempted to leave the cover off after any routine servicing or maintenance. The system can run just fine without it, so long as it doesn't get damaged, or objects get caught in the sump pit possibly causing failure. You will probably never even know about any such damage until you need your basement sump pump the most.
One final advantage is the dust and dirt that is kept away from the workings. Keeping this dirt away helps keep the system from overheating and ensures a long service life of your sump pump system. There's really no disadvantage to using a sump pump cover. Without one, you risk premature failure when you need your sump pump the most.