Take Notes During Low Water
As I walked along the high bank of a local lake a few years ago, I was astounded how low the water was. The shallower arms of the lake were quite a bit narrower and since it hadn't rained in a long while, the visibility was outstanding!
As I scanned the water while moseying towards my destination, a slight change caught my eye through my polarized glasses—a small dark patch, maybe 8 feet by 8 feet in size. I had walked along this section many times before, but with the water being this low it was just enough to faintly reveal this new curiosity. Weeds? A rock pile?
On the first cast it was clear what I had found—an isolated grouping of very craggy rocks. Whether they were put there on purpose or were naturally occurring I don't know, but I do know I caught a nice 3-pound largemouth right along the edge of them after a couple minutes of casting. In a lake with mostly mud and silt bottom, this was a heck of a find. I made note of the exact spot to cast from, lined up the rock pile with a couple of landmarks, and filed it all away in my mental notes. Needless to say, it's been a productive spot ever since!
It doesn't matter whether you're targeting trout or any number of other species; identifying where the key zones are and fishing them thoroughly will eliminate a lot of wasted time and effort.
Often, some of this awesome water is really obvious to even a beginning fly angler. Slack water behind a big boulder, a deeper undercut bank, fallen limbs laying down into the water—all common examples of productive areas. But, what about some of those juicy zones below the surface that you can't readily see when the water is at more typical heights?
When the water gets low and clear, one advantage anglers have is that visibility through the water improves. This potentially lets you see to the bottom in more places more easily. Regardless of how the bite is or if I'm even fishing at all, I absolutely love scoping out low water conditions because it allows me to see stuff that might otherwise be hidden from view. This goes for rivers, lakes, or even an extreme low tide in saltwater. Being able to see the normally unseen or to simply get a sharper look at an area's layout can pay off in a major way not only on that day, but also later on when the water rises and obscures the view once again.
This is a key time to note things like:
Changes in Bottom Contour- Deeper water is often the key to great fishing. It's hard to miss the darker blue or green of a well-defined drop-off, but when the water is down it can also help you to better understand the general layout or see key areas within that deep zone that may attract more fish. At other times of the year, you may have noticed that you typically catch more fish in one section of that deeper water while "blind fishing." During low water, you just might get to see exactly why this is. It's also a great time to locate those more subtle depth changes—small depressions or slots that you may not have even known existed.
Structure and Cover- Being an avid bass angler, these are perhaps my favorite things to look for when the water drops. I already mentioned rock piles, but there's a lot of possibilities here ranging from wood, an isolated boulder, discarded Christmas trees, or even man-made junk. Once in a Miami waterway during winter, we spotted a peacock bass hanging by a sunken lawn tractor! These pieces of structure and cover might be completely uncovered and in plain sight, or you may need to scan the water to look for submerged objects. Even when the visibility is excellent, scan slowly because sometimes they can still blend in quite well. The slower you look, the more subtleties you'll have a chance at noticing.
When you find a key area you'll want to revisit time and time again, try using visual cues to help give you a "line" on where to cast during times of higher water or dark skies. For instance, when it comes to my rock pile spot, I know to stand about 20 feet left of a certain tree while casting 30–40 feet towards the tip of a point across the way. If what you want to fish is visible through the lens of a camera phone, taking a picture is another idea to help you remember exactly where a given spot is.
The water can be low in many areas this time of year, so get out there and do some scouting.
If you can go on a windless, sunny day and have access to higher ground, all the better. It can be really surprising what you'll find and learn while just walking and examining. Being able to get more of an in-depth look at how a particular area is laid out is an incredible advantage that allows you to better approach and understand that zone at all times of the year. Part of being a great fly angler also means being a great observer!