WORTH NOTING ON TV

* FRIDAY

The Elephant Wars (CNN, 3:30-4 p.m.): It's elephants vs. people, according to this special about a major conservation issue in Africa. As more of the elephants' ranges are settled by mankind, the animals are driven to foraging in farms and villages, not only destroying crops and buildings but sometimes killing people.

This program deals with problems and measures being taken to meet them in Kenya, Zimbabwe, and other African countries. Besides old techniques like building barriers or driving herds away, the program covers new approaches like contraceptive vaccines and hauling herds of tranquilized elephants to open areas hundreds of miles away. * SATURDAY

International Mixed Pairs Gymnastics (NBC, 2:30-3:30 p.m.): Men and women compete as teams - it's a little like the pairs competition in skating - in this special version of gymnastics taped in West Palm Beach, Fla. During three rounds of competition, the female and male gymnasts perform, then the two scores are combined for a total. Top entries from 18 countries are expected to take part - including Olympians. * SUNDAY

Booknotes (C-Span, 8-9 p.m.): The guest is Norman Ornstein, author of ``Debt & Taxes: How America Got Into Its Budget Mess And What To Do About It.''

Loch Ness Discovered (Discovery Channel, 9-10 p.m.): Stories of the Loch Ness Monster started circulating about 575 AD, and since then no amount of attention has seemed to quench the public appetite for news about it - if ``it'' exists.

This special offers the results of a month-long scientific survey sponsored by the Discovery Channel, which says this is the first ``multi-disciplinary'' undertaking of its kind. Last summer, teams of researchers used sonar and infra-red photography to explore the lake and try to determine, among other things, if there are enough fish in the lake to support such a creature. The show also supplies photos and accounts by eyewitnesses of alleged ``Nessie'' sightings.

Please check local listings for these programs.