In order to develop a Watershed Management Program responsive to the needs of the streams and watersheds, an evaluation of the streams throughout the County was necessary. The field evaluations were conducted by two person teams performing habitat assessments and stream corridor inventories while walking approximately 440 miles of streams within the County. The assessments were conducted on all streams in the County with 100 acres or more of drainage area.

HABITAT ASSESSMENTS

To evaluate the physical characteristics of the streams, the County used a variation of the habitat assessment included in the Georgia Rapid Bioassessment Protocol that was based on the Environmental Protection Agency’s Rapid Bioassessment Protocol. The protocol provides a dual assessment system based on stream energy – one for higher energy, riffle/run systems and one for lower energy, glide/pool systems. For each of these systems, 10 habitat parameters are evaluated.

For high energy, riffle/run systems the following parameters were studied:

  1. Instream cover
  2. Epifaunal substrate
  3. Embeddedness
  4. Channel alteration
  5. Sediment deposition
  6. Frequency of riffles
  7. Channel flow status
  8. Bank vegetative protection
  9. Bank stability
  10. Vegetated buffer zone width

For low energy, glide/pool systems, the following parameters were studied:

  1. Bottom substrate
  2. Pool substrate
  3. Pool variability
  4. Channel alteration
  5. Sediment deposition
  6. Channel sinuosity
  7. Channel flow status
  8. Bank vegetative protection
  9. Bank stability
  10. Vegetated buffer zone width

STREAM CORRIDOR INVENTORY

While conducting habitat assessments for the streams, an inventory of other stream influences and conditions was also collected. Many of these items can and are having a negative impact on the streams within the County. These included illicit discharges, streambank erosion, dump sites, lack of stream buffers, exposed and possibly leaking sanitary sewer lines, and stream blockages. Identifying these problem areas is an important component of the overall watershed program. Undiscovered and subsequently unaddressed, these problem areas will continue to impact the stream systems, often causing significant physical, biological and chemical degradation.

OTHER STREAM INFORMATION

Certain segments of the waterways within the County are listed in various state and federal programs for not meeting current water quality standards. The waterways (or segments of waterways) currently listed on the Department of Environmental Quality’s Schedule for Development of TMDLs through 2010 are identified as follows:

Stream

Stream Segment

Length (miles)

Square Miles

Impairment

Almond Creek

 

3.3

 

Fecal Coliform

Tuckahoe Creek

Route 6 bridge to James River

4.7

 

Dissolved oxygen

Fecal Coliform

James River

Boulevard bridge to Fall line

3.2

 

Fecal Coliform

General Standard (Benthic)

James River

 

 

10.8

Nonpoint Source

Combined Sewer Overflow

White Oak Swamp

White Oak Swamp Creek to Chickahominy River

6.7

pH

Fecal Coliform

Upham Brook

Upham Brook Pump Station to Chickahominy River

5.8

Fecal Coliform

Fourmile Creek

Deerlick Branch to Grigg’s Pond

 

pH

Fecal Coliform

 

Although impairment scores are not identified, it is reasonable to conclude that possible sources of the impairment(s) could be addressed by the Stream Assessment / Watershed Management Program. However, there is information available that indicates certain impairments could be due to a natural occurrence. Therefore, certain stream segments warrant further investigation to determine the cause of the impairment and their watersheds have been designated as Special Study Areas. These areas are shown on Map 2.1.