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Hawlings River Subwatershed

The Hawlings River, located in the northeastern part of the County, originates near Etchison just below the intersection of Routes 108 and 650. The Hawlings flows into the Patuxent River between the Triadelphia and Rocky Gorge reservoirs.

As a major tributary to the Patuxent, the Hawlings plays an important role in the overall efforts to reduce nutrient and sediment loadings to this river and, in particular, to the Rocky Gorge reservoir, a public drinking water supply. Much of the Hawlings River subwatershed, particularly above the Reddy Branch tributary, is currently in open or agricultural land, public parkland, or newer large-lot residential areas.

Image of Rachel Carson Park


A Journey Through the Hawlings River

The Hawlings River and its tributaries are included in the Patuxent Primary Management Area (PMA). The PMA is a stream buffer and transition zone within which land uses are closely managed to reduce nonpoint source runoff and nutrient loads, and to improve and protect stream conditions. The ultimate goal for the primary management areas along the Patuxent River and its tributaries is to maintain low-density, low-intensity land uses within 1/4 mile of the mainstem and within 1/8 mile of tributaries, and to actively establish a minimum 50-foot forested buffer strip along all streams. 

The Hawlings River passes through three distinct land uses.

  • The upper subwatershed east of Laytonsville and above Sundown Road remains mostly in rolling agricultural lands. This headwater area has many small tributaries that combine to create the Hawlings River mainstem.
  • The middle section passes through a narrow, rocky valley area where the velocity of the stream increases. The Rachel Carson Conservation Park contains some of the best stream habitat in the subwatershed.
  • Below Georgia Avenue, the stream passes through a sandy loam floodplain. The change to sandy soils and the addition of uncontrolled storm flows from the Olney Mill tributary have caused severe bank erosion and scour pools.

The tributaries flowing into the Hawlings from the southwest, including James Creek and the Olney Mill tributary in Reddy Branch, contain much higher densities than in the rest of the subwatershed as a result of development in and around the Olney Town Center. The resulting higher impervious conditions have contributed to degradation of stream conditions in certain areas.


The Health of the Hawlings River Subwatershed

A cool-water fish community can be found throughout the subwatershed. Shield darters are found in the lower Hawlings River as well as the Patuxent River mainstem. They have been reported in the Little Paint Branch but are found nowhere else in the County. Large sunfish and fallfish are found in the lower reaches of the Hawlings. Some reports of wild trout being caught usually end up as large, feisty creek chubs that have risen to the bait and lures of local anglers.

Overall, the Hawlings River, particularly the mainstem, continues to maintain good resource conditions. The state designation Use IV-P is based on temperature and dissolved oxygen standards that could support adult trout (the -P indicates that this area drains to a public drinking water supply). Below Georgia Ave., however, stream habitat conditions degrade with large areas of bank erosion, scour pools, and sediment deposition. A combination of approaches is necessary for this subwatershed in order to protect, improve, and restore biological resource conditions.

The Hawlings River Subwatershed Restoration Study & Action Plan (PDF, 1MB) as completed in February 2003. This Plan is a dynamic document used to track progress in implementing the study recommendations. This plan along with the Patuxent Watershed Implementation Plan describe the greatest improvements for existing degraded in-stream habitat as well as provides the best opportunities for reductions of sediment and associated pollutants for the area. The Hawlings River is also a part of the Patuxent River Reservoirs Watershed Protection Program.


How Can I Help the Hawlings River Subwatershed?

Individuals interested in the health of the Hawlings River can contact the Patuxent Riverkeeper or the Patuxent River Commission to learn how they can help protect this resource.