Introduction Ingraham Hwy & Homestead Canal Construction Culverts Airborne Resistivity Tables References PDF Version

Construction of the New Road, S.R. 9336 (S.R. 27)

Increasing vehicle traffic in the late 1940's and early 1950's after creation of Everglades National Park necessitated improvements to the narrow and frequently inundated road to Flamingo. Re-alignment along the north side of the Long Pine Key rock ridge replaced much of the original Ingraham Highway (Fig. 3). Construction of the southern portion of what was then called S.R. 27 and is now known as S.R. 9336 began at Flamingo in 1956 and proceeded northward. During the construction of S.R. 9336 178 culverts were placed under the road from the Park entrance to Coot Bay (Fig. 3). These culverts were constructed to help reconnect the wetlands, maintain the flow of water and prevent flooding of the road during periods of high water. Simultaneously with the construction of the southern portions S.R. 9336 the Homestead canal was filled. The fill needed for the construction of the new road was obtained by digging a series of borrow pits instead of a continuous borrow canal along the side of the road.

Figure 3: New road alignment. Source soil assocations: [ 17 ]. [larger image]

Today, S.R. 9336 (S.R. 27) enters Everglades National Park on the Long Pine Key rock ridge, which has some of the highest elevations in the southern portion of ENP. This ridge is the terminus of the Atlantic Coastal Ridge and is made of an oolitic facies of inorganic origin. The road follows the northern edge of this ridge, until it crosses over the marl soils near Mahogany Hammock. Along its northern alignment the road heads west through pinelands broken only by a couple of transverse glades which cut through the relatively high elevations, four to five feet above sea level. Today, with sharply reduced water levels, this terminus of the coastal ridge forms a more effective barrier with the only conspicuous surface water flowing through Taylor Slough and occasionally through the smaller glades to the west that cut through the pinelands. The predominant direction of the historical surface water flow pattern in this reach is southward toward Florida Bay, at right angles to the road. The substrate is mostly rocky pinnacle limestone, Miami oolite, and where not exposed is overlain by the Perrine and Flamingo marls, an algae-based calcium carbonate deposit.

After passing the Pa-hay-okee overlook the road heads southwest, crossing mixed grass prairies and cypress domes, until it reaches the eastern edge of Shark Slough near the Mahogany Hammock overlook. The soil in this stretch is Perrine marl. South of Mahogany Hammock, the road takes a more north-south bearing, through an area dominated by prairie with hardwood hammocks scattered throughout. By now, the average elevation has dropped several feet, to one to two feet above sea level. By the time the road approaches the Nine Mile Pond turnoff (Fig. 7), the landscape has become scrub mangrove forest. Peat soils appear in the area, which tend to be thicker in the mangrove zone and water now flows more toward the southwest. This stretch of the road is close to the coast where tidal forces become more influential. The road terminates in Flamingo, where concessions and access to Florida Bay is made available by the National Park Service.

Roads connecting to S.R. 9336

Roads leading to the Park's maintenance area and visitor vista along areas along S.R. 9336 also may play a role in altering water flow. The Pine Island road leading to the maintenance area is crossed by culverts at two locations. The first location has one 24-inch culvert and the second location contains three 24-inch culverts and one 36-inch culvert adjacent to one another. Royal Palm road contains fourteen 24-inch culverts and one 36-inch culvert. The road to the South Florida Natural Resources Center contains only one 36-inch culvert. This access road serves as an additional barrier to water flowing through the small glades that cut through the pinelands north of the road. South of this road is the area known as the Hole in the Donut, an area which until June 1975 had been under cultivation. Natural vegetation, mostly short-hydroperiod marshes, have been replaced by the Brazilian pepper tree (Schinus terebinthifolius). The exotic vegetation and ground surface alterations prove to be a barrier to surface-water flow. Pay-hay-okee road has six 24-inch culverts. Mahogany Hammock road contains eight 24-inch culverts, spaced 0.2 miles apart. In addition to the main road culverts, the Pay-hay-okee Road and Mahogany Hammock road culverts were monitored for discontinuous flow and stage levels starting during the 1996 wet season. This will further help understand the flow patterns in the study area.

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