Changes in Dyke Marsh over Time, Using the Fairfax County Historical Imagery Viewer
Fairfax County’s historical imagery viewer enables people to see aerial images of Dyke Marsh that show changes over the years. These images show the significant loss of marshland from the dredging that hauled away over half the marsh and after a protective promontory was removed from the south end of Dyke Marsh.
The two images below from the viewer show aerial views of Dyke Marsh in 1937 (left) and in 2021 (right). At the top you can see that the country club golf course was built on fill over what used to be water. At the very bottom you can see the natural promontory in the 1937 photo and the breakwater that replicates the former promontory built as part of the multi-year restoration effort currently underway. Between the top and bottom you can see the significant erosion that took place over the years. Two U.S. Geological Survey Studies found that the dredging destabilized the wetland system. See “Restoration” on this site.
The Fairfax County site allows you to compare views of the marsh from many different years between the 1937 and 2021 dates. To view the map, click here. To view Dyke Marsh and see changes over the years, put "93-2" in the search box and click to search. You can close the text boxes that block part of the view of the aerial map. Use one finger to move the map so that your screen has the area of Dyke Marsh that you wish to view. Use two fingers (very carefully) to zoom in or out on the map. Once you have the area on the screen that you wish to view over the years, click on "Layer List" icon at the bottom of the screen.
To start viewing different years against the latest map, make sure "2021 Aerial Photography" and one other year are checked. We suggest using "1937 Aerial Photography" as the second map. You may close the Parcels, County Border and Tax Map Grid layers to simplify your view. Close the layer list dropdown. At the lower left on the screen click on the "Swipe" icon. This is a toggle button that turns the swipe function on and off.
On the right side of your screen should be a small gray box with a white left arrow. Click and hold down while you pull the box to the left to view the older map and to the right to view the newer map.
While in this view, you can click again on the layer list icon to change the two years you wish to compare. If the map does not change when you pull the arrow left and right, go to the "Swipe layer box" at the bottom, click on the down arrow and select the most recent of the two years you selected to view. You should then be able to see both images as you swipe.
If you live in Fairfax County and would like to try this in your neighborhood, go back to the first screen (you can exit and go back to the historic imagery viewer). Double click on the map for the location you are seeking to zoom in slowly and move the map until you see your neighborhood. This may take a little trial and error. Once you get there, you can change the layers and use the swipe function to see changes over the years.