OK guys, I'll try to hit the highlights of your comments with some background.
A few years after the course was opened, there was a desire to add more length because of the distances the college men were hitting the ball (if you've seen it up close, you know what I mean). Also, Notre Dame would like to host a National NCAA tournament so the feeling was to get the course over 7000 yards.
A new back tee was added to hole 3, expanded teeing ground on 4, new back tees on 6, 7, 8, 11, 15, 17 and 18. In the original routing, holes 16 and 17 went further toward the northeast corner of the property. The owners of the land refused to sell so the routing was adjusted. Hole 16 became shorter and the original tees for hole 17 are shown on the right of the third photo from the bottom. North of the original tees for 17 was a dumping ground. From that area up to the Toll Road, excess dirt, sod from the stadium and other items were dumped. To my understanding, the mounds just off the tee were a by product of this work. When the new back 17th tee was proposed, a valley was cut through those mounds and a bunker was added just prior to the fairway. Before the back tee was added, most of the college players could get to the green with a driver and mid iron. The long hitters were getting home with a driver and 7-9 iron. The new tee added 85 yards.
The creek running through the property is Juday Creek. When the project began, the creek was essentially void of any wildlife. It was stagnant and too warm. The DNR was quite involved in the project and the creek had to be addressed. To the left of the bridge on 16, a new creek bed was built moving slightly north and into the trees. A few turns were added to the creek that cuts across hole 16 to improve flow. The old creek bed is what runs down the left side of 18. When the creek emerges from the trees and cuts across 18, it rejoins the original creek bed. To the right of the bridge on 18, the creek again was split and rerouted right into the trees where it can be found behind the 10th green. The original creek bed cut across the 10th fairway. Both of the old creek beds on 10 and 18 are recirculating creeks. The original design of 10 had the old creek bed as a large waste bunker. It was then changed to the existing creek about a month prior to the Big East Championship tournament in 2000. From the DNR's perspective, the creek project was a huge success. Steelhead now spawn up the creek from the St. Joe river and can be seen from the bridges on 16 and 18.
Hope this answers some of the questions!
Ken