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The Little Seneca Creek Watershed 

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The Little Seneca Creek watershed is a large sub-basin of the Great Seneca watershed and drains a significant portion of the western part of the County. The stream system originates slightly south of Damascus and drains areas of Clarksburg, Germantown, and Boyds before flowing into Great Seneca Creek just above Route 28 at Dawsonville. Little Seneca Lake, located near Boyds, is a large regional impoundment that serves as an emergency water supply source. This lake is the focal point of the Black Hill Regional Park and is known regionally as a prime location to view wintering waterfowl. The lake has been stocked with tiger muskie, largemouth bass, bluegill and channel catfish. Little Seneca Creek upstream of the lake is designated recreational trout waters by the state (Use IV-P) due to temperature and dissolved oxygen standards which make it suitable for an adult trout "put-and-take" population. Downstream of the Little Seneca Lake dam, cold water discharges from the deeper part of the lake water column enable a natural trout waters designation (Use III-P) to the confluence with Bucklodge Branch. Rainbow and brown trout are found in this section, as well as a diverse cold-water community. Beaver have impounded large areas of Little Seneca below the lake and massive beaver dams can be found 5 to 6 feet high.

Portions of Upper Little Seneca Creek and Ten Mile Creek have been shaped by geological forces unique to this part of the County. A fracture fault line runs through these and the adjacent Little Bennett watersheds. These fault lines have influenced the channel morphology dramatically. The Ten Mile Creek watershed has an incredibly diverse and sensitive benthic macroinvertebrate community. Many different stoneflies and mayflies can be found in this high quality stream. During warm winter days in late February, winter stoneflies emerge in large numbers and can be seen flying against the snow.

The Little Seneca watershed has a very mixed character of land uses, including rural areas around Boyds and the west side of Clarksburg, and higher density land uses in Germantown proper. Located along I-270, both Clarksburg and Germantown are "corridor communities" in the County's General Plan, and contain existing and planned development in support of the County's housing and job needs. Southwest of Germantown, land uses in the watershed are typical of the agricultural reserve, with a mixture of farms and large-lot residential areas, interspersed with commercial uses at several cross-roads.

Extensive planning efforts have occurred as part of the Germantown Master Plan and Clarksburg Master Plan to protect stream quality in Little Seneca Creek. These efforts include density limitations, stream valley park acquisition and dedication, reforestation, and designation of a part of Clarksburg as a Special Protection Area (SPA). SPA regulatory requirements include enhanced plan review, stream monitoring, and BMP performance monitoring for new development.

Over time, the character of the watershed will change considerably, as the corridor cities develop. The upper sections of the watershed are still in good condition and should benefit greatly from the planning efforts that have occurred to protect water quality. Efforts taken now to address existing channel erosion and instability in the downstream reaches will be valuable in protecting the overall stream system from smaller cumulative impacts as the headwaters develop. This is particularly important for the tributaries in the Germantown area that discharge downstream of the lake. These tributaries have a much more direct effect on the portion of Little Seneca now designated as natural trout waters (Use III-P).

Little Seneca Creek Stream Condition, Habitat Conditions, and Management Category Designation

Subwatershed/

Stream Condition

Habitat Condition Primary Factors Affecting Stream Condition Unique Characteristics and Management Category
Upper Little Seneca nonSPA - EXCELLENT EXCELLENT Forested areas are prevalent and headwaters are currently protected in Ovid Hazen Wells Park. Area contains many springs and seeps.

Watershed Protection Area - special

Upper Little Seneca SPA EXCELLENT EXCELLENT Headwaters portion of the Little Seneca immediately downstream of Ovid Hazen Wells Park.



Existing Regulatory Special Protection Area
Upper Little Seneca

South - GOOD

GOOD  

Existing Regulatory Special Protection Area
Town Center Trib. - EXCELLENT GOOD Years of agricultural use have added fine sediment to the stream.

Existing Regulatory Special Protection Area
L. Seneca -

White Ground -

GOOD

GOOD Stream bank condition and riparian zone changes from excellent in the upper reaches to good as the stream passes through agricultural areas in this section.





Existing Regulatory Special Protection Area
Cabin Branch - GOOD GOOD Upper reaches are in open agricultural fields - some forested stream buffers. Water temps observed to be in UseIII range in 1994.

Watershed Protection Area - special

Upper Ten Mile Creek - EXCELLENT EXCELLENT to GOOD downstream Upper reaches are heavily forested with numerous springs and seeps. Fracture/fault geology influenced stream morphology.

Existing Regulatory Special Protection Area

Lower Ten Mile Creek - GOOD GOOD Backwater from the lake has caused sediment deposition/bank slumping.

Watershed Protection Area - regular
West Seneca Lake - POOR FAIR Poor bank stability and high levels of sediment deposition. The rural density transfer zoning in this area will limit future increases in impervious area.





Existing Regulatory Special Protection Area
Milestone Trib. - EXCELLENT (Preliminary) EXCELLENT

(Preliminary)

Land use in this area includes the Milestone Development Area with significant areas of high density commercial and residential areas. A unique wetland of special state concern - the Germantown Bog (which is actually a fen) - is located in this area. This type of wetland community is typically found further west in the state associated with the Allegheny Plateau. Significant efforts have been made to protect the area from impacts of master-planned land uses.

Watershed Protection Area - special

Churchill Trib. no current data Land use in this area includes the Germantown Town Center with significant areas of high density commercial and residential areas.



Watershed Protection Area - regular
Germantown Estates Trib. - GOOD (prelim.) FAIR (preliminary)  



Watershed Protection Area - remedial
Brodsky Trib. - POOR (prelim.) GOOD (preliminary)  

Watershed Protection Area - remedial
Boyds Tribs. - FAIR

(preliminary)

FAIR

(preliminary)

Channel exhibiting signs of accelerated downcutting with limited access to floodplain, resulting in entrenchment and channel erosion.



Agricultural Watershed Management Area
Unnamed Trib. - POOR (prelim.) POOR

(preliminary)

Unpermitted landfill in operation during early '90s.

Agricultural Watershed Management Area
Hoyles Mill Trib. - GOOD GOOD Sediment is a problem in pools in upper reaches. Lower stream reach is forested wetland.

Agricultural Watershed Management Area
Bucklodge Branch - GOOD GOOD Some sediment deposition and embeddedness problems occurring. Reference site for Md. DNR

Agricultural Watershed Management Area

Lower Little Seneca - GOOD (prelim.)    

Agricultural Watershed Management Area

Little Seneca Creek Watershed Management Categories

Until fairly recently, much of this watershed consisted of rolling farmland. Changes from agricultural to suburban land use bring inevitable increases in impervious area. However, due to the planning efforts undertaken and improvements in environmental regulations and guidelines, these changes in Little Seneca will be accompanied by stormwater management, stream buffers and reforestation of riparian areas. Unlike many older areas of the County which developed without stormwater management, this should mitigate development impacts substantially. Existing problem areas showing instability from past land use and clearing activities need to be addressed to help avoid stream degradation as changes in hydrology occur in response to increased watershed development.

Watershed Protection Areas

Special level of protection - Existing Regulatory Special Protection Area

The County Council designated portions of Upper Little Seneca within the Clarksburg Planning Area as a Special Protection Area (SPA) in recognition of the special level of protection that would be needed to protect stream resources in the vicinity of the Town Center. Areas east of I-270 and portions of Ten Mile Creek west of I-270 were included in the SPA designation. Ten-Mile Creek is an example of a sensitive area needing special protection where two different management approaches were combined to achieve the end result. SPA designation protects the drainage where high density land uses were located along I-270, and low density land use zoning was employed on the western side of Ten-Mile Creek.

Watershed Management Strategy
  • Application of Special Protection Area regulations for stream protection (Chapter 19, Art.V)

Special level of protection

This category includes the areas above Seneca Lake outside the designated SPA, and the Milestone Tributary. The Milestone tributary is identified as needing special levels of protection, which has been provided through various efforts in the Germantown Master Plan and modeling, monitoring, and unique stormwater management controls designed to help ensure that the fragile Germantown bog area is not detrimentally impacted by proposed development.

Watershed Management Strategy
  • Continue efforts through implementation of master plan recommendations and development review procedures to protect this sensitive area.
  • Provide targeted public education for residents, businesses and developers about the subwatershed resources and stewardship opportunities.

Remedial level of protection

The Germantown Estates tributary and Brodsky tributary are recommended for remedial management efforts to address existing problems in these stream reaches.

Watershed Management Strategy
  • Continue monitoring efforts through development review requirements and DEP baseline monitoring program to assess subwatershed conditions and effects of new environmental protection features such as stream buffers and state of the art stormwater controls.

Regular level of protection

The Churchill tributary is placed in this management category until further monitoring data is available to identify stream condition and refine a management approach.

Watershed Management Strategy
  • Further study stream condition and land use relationships to refine management approach.
  • Continue application of environmental guidelines and regulations and other regular protection tools.

Agricultural Watershed Management Areas

South of Boyds, land uses remain predominately agricultural in character, however, several areas of large-lot residential uses are cropping up. Efforts to improve riparian buffers, particularly in the area below Route 117 are particularly needed, as well as measures to address entrenched channel conditions. Efforts have shown that allowing a forested buffer to develop adjacent to streams is very effective in lessening the severity of channel erosion and instability problems on cultivated areas.

Watershed Management Strategy
  • Promote voluntary implementation of best management practices, particularly establishment of forested riparian buffers.
  • Public education and outreach to landowners to increase awareness of the importance of stream valley buffers, which are a key feature of environmental protection in these areas developing with larger lot sizes.

Watershed Restoration Areas

Two areas have been identified as needing restoration to address serious problems which have led to poor stream conditions: West Seneca Lake tributary and Unnamed tributary.

Watershed Management Strategy
  • Pursue cooperative partnerships with individual land owners and the County to provide improvements in these areas, as well as pollution prevention education and efforts.

Maps

Land Cover Impervious Area Stream Condition Management Categories
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Land Cover Graph

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Last edited: 10/13/2004