In Middletown, a Cuesta Drains Runoff to the Bay or to the Navesink

Every time it rains, water flows over lawns, parking lots, and streets. Stormwater runoff travels along gutters into catch basins and storm drain pipes that flow into local waterbodies. Along the way, stormwater picks up trash, gas, motor oil, antifreeze, fertilizers, pesticides, and wildlife and pet droppings.

Depending on where you live in Middletown, whenever it rains the runoff from your lawn is polluting either Raritan Bay or the Navesink River.

This is because of a ridgeline called the Mount Pleasant Hills that divides Middletown into two watersheds that flow either north to Raritan Bay or east to the Navesink River.

The Mount Pleasant Hills

The Hills are a cuesta, which is a long ridge with a long gentle slope on one side and a steep eroding slope on the other called an escarpment. It extends throughout Monmouth County - west from the hills of Highlands to Holmdel, where it turns southwest through Imlaystown in Upper Freehold to the Delaware Bay in Salem County .

The only map of the Hills or the watersheds that I could find online is a relief map on a NJDEP webpage for Watershed Management Area 12 in Monmouth. If anyone finds a better map please post the link and I will edit it in.

Mount Mitchell in Atlantic Highlands is part of this ridgeline and a 266 feet above sea level is the highest point on a shoreline of the eastern seaboard south of Maine. To the west, the Mount Pleasant Hills range in elevation from 200 feet at Chapel Hill, Middletown, to 391 feet at Crawford Hill in Holmdel, which is the highest point in the County. West of Morganville in Marlboro, the Hills only rise to 100 feet or so, but near Perrineville in Millstone they rise again to nearly 360 feet before leveling out again to about 100 feet near Imlaystown.

The Hills split all the streams in Monmouth County into three major watersheds. Streams to the north of the Hills flow into Raritan Bay, and to the east of the hills they flow to the Atlantic Ocean, or to its estuaries like the Navesink and Shrewsbury rivers. Streams to the west of the Hills flow to the Delaware River and south into Delaware Bay, or to the Raritan River, north and east to Raritan Bay.

These hills have been able to resist eroding over the past 10 million years because they are held together by a marl clay called glauconite, and blocks of iron-cemented sand called limonite or siderite. When they contain quartz pebbles these iron minerals are called peanut stone, which is used around Atlantic Highlands to build fences, buildings, and bridges.

Where the Ridgeline Splits the Watersheds in Middletown

In Middletown, the watershed divide is the hill that crests at Red Hill Road near Church Lane across from Tatum Park. On the northern side of this hill towards the train station, runoff flows to Raritan Bay, on the southern side of the hill it flows towards the Navesink River. This is also where the headwaters of three subwatersheds come together: Waackaack Creek and Comptons Creek drain to the Bay, and Poricy Brook drains to the Navesink.

The ridgeline crosses Middletown-Lincroft Road south of the train station at the hill near Iler Drive, and crosses Route 35 near Woodland Drive by the Outback Restaurant.

It more or less follows Kings Highway East until the road is renamed Monmouth Avenue near Atlantic Highlands. It cuts north across Route 36 near the Thousand Oaks development and follows Ocean Boulevard and Hillside Road on the Bay in Atlantic Highlands.

At Mount Mitchell it recrosses Route 36 near Scenic Drive where it becomes the ridgeline of Hartshorne Woods that towers over Route 36 until it descends into the Navesink and Shrewsbury Rivers near the entrance to Sandy Hook.

RESOURCES

Boyd, Paul. 2004. Atlantic Highlands – From Lenape Camps to Bayside Town. Arcadia Publishing. Charleston, S.C.

Dahlgren, P. 1977. Geology of Monmouth County in Brief. New Jersey Geological Survey.http://www.state.nj.us/dep/njgs/enviroed/county-series/Monmouth_County.pdf

Monmouth County Planning Board. 1975. Natural Features Study for Monmouth County. Freehold, NJ. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=14&cad=rja&ved=0CDEQFjADOAo&url=http%3A%2F%2Frucore.libraries.rutgers.edu%2Frutgers-lib%2F16850%2FPDF%2F1%2F&ei=MUApUt6_L9an4AO55IDoCg&usg=AFQjCNFi5DSjl07oUjIymynpCh27E4b8FQ

Monmouth County Planning Board. October 31 , 1978. The Changing Shoreline: Managing The Coastal Region. Monmouth County, New Jersey. Freehold, New Jersey. http://www.gpo.gov/fdsys/pkg/CZIC-gb450-c43-1978/pdf/CZIC-gb450-c43-1978.pdf

New Jersey Department of Environmental Protection. Clean Water NJ. http://www.cleanwaternj.org/faqs.html 

Stanford, Scott. 2005. The Geologic History Of New Jersey's Landscape. Unearthing New Jersey. Vol. 1, No. 2. New Jersey Geologic Survey. New Jersey Department of Environmental Protection. http://www.state.nj.us/dep/njgs/enviroed/newsletter/v1n2.pdf

United States Geological Survey. 2003. Geology of the New York City Region. http://3dparks.wr.usgs.gov/nyc/