Today, nine months later, no repairs have been made to the dam; nor has the small lake behind it been even partially drained.

The dam is jointly owned by people who live next to the lake, some in homes worth more than $100,000. They contend that the dam is safe and that they cannot afford the repairs. They do not want to drain the lake because that would lower their property values. And, as the wife of one the homeowners says, "Springtime is just around the corner; there's fishing in that lake."

Across the nation, the Corps of Engineers has inspected more than 4,500 dams that, if they broke, could result in loss of life, high property damage, or both. So far, 1,343 -- or 29 percent of them -- have been found to be in "unsafe" condition.

Of these unsafe dams, no corrective action has been taken on most of them since the findings were made public, says George Gibson, a dam-safety official with the Corps of Engineers in Washington.

Most states either have no regular dam safety inspection programs or have inadequate staffs to follow up on the Corps of Engineers's findings. And many dam owners are balking at the cost of repairs involved.

The national inspection program was ordered by President Carter shortly after a dam burst near Toccoa, Ga., in November, 1977, killing 39 persons. The program, due to be completed in two more years, has:

* Focused attention on dam safety. Several states have passed dam-safety programs since the Corps of Engineers's inspections began.

* Identified many unsafe dams, some of which have been repaired.

Many of the unsafe dams, similar to the one the Dennis family can see from their home, were built years ago in once-rural areas that have since attracted housing developments. Few states had regular dam-inspection programs. Newcomers assumed the dams were safe.

Other dams on the Corps of Engineers's growing unsafe list are owned by companies or state or local governments.

The dilemma is how to get the rest of the unsafe dams repaired or drained.

The Corps of Engineers has no authority to do repair work except on dams in an "emergency unsafe" condition, says Jack Thompson, assistant chief of its engineering division. Some 68 dams have been found to be in an "emergency unsafe" condition, but almost every one has been temporarily drained or breached , says Mr. Thompson.

The Omnibus Water Resources Bill, nearing final passage in the US House of Representatives, contains a provision for 50-year, medium-interest loans to state or local governments for repair work. No assistance is offered private dam owners.

But private owners of dams often contend that they, too, deserve assistance.

The owners of the dam above the Dennis home are paying costly attorney's fees to fight state orders to repair or breach the dam. If it has to be repaired, residents say they want the state to pay for all or a major part of the work.