Gales Creek Large Woody Debris Inventory Report

All of the surveyed reaches contained pieces of LWD within the stream’s bankfull width and in the recruitment zone (Table 2). The 200-ft segments averaged 15 pieces of LWD instream and in the recruitment zone, combined (n = 26; 8 pieces LWD per 100 ft). All segments averaged 2 pieces of instream LWD (n= 26; 1 pieces LWD per 100 ft) and 14 pieces of recruitment zone LWD (n= 26; 7 pieces LWD per 100 ft). Recall that the recruitment zone for this study was defined as 50 ft from the stream’s bankfull mark. Instream numbers reflect wood counted within the stream’s bankfull mark. There were no live, qualifying, coniferous trees observed within the survey.

Reach GL05 contained the highest total number of instream and recruitment zone LWD. The greatest number of perched or dead trees within the recruitment zone occurred in reach GL08 (Table 2). The majority of LWD within all reaches (82.5 %) fell into the 1-2 ft diameter class (Table 3). Debris jams were found infrequently throughout the surveys, with a total of five found throughout the 5,000 ft of stream sampled. When these debris jams did occur, 40% demarcated a break in habitat types, from pool to riffle or glide (Table 4). This may be viewed as the ability of LWD jams to create habitat heterogeny in Gales Creek.

Habitats encountered within the reaches were glides, pools and riffles. Stream temperatures ranged from 10 to 15 °C throughout the surveys; air temperatures ranged from 6 to 18 °C. Land use in the surveyed portion of Gales Creek is primarily agricultural with some forested and rural residential lands. A synopsis of the LWD survey in each reach follows.

GL02

Reach GL02 begins at the confluence of Gales and Kelly Creeks and extends upstream approximately 3,100 ft (Figure 2). Habitat types in GL02 include riffles, glides and pools with a mean gradient of 1% (Figure 3).

The air temperature and water temperature at GL02 were 8 °C and 10 °C, respectively. On average, GL02 had 16.0 pieces LWD per 200-ft reach. A total of 80 pieces of qualifying wood were observed within the survey, with one piece observed within the stream. The remaining 79 pieces were observed within the recruitment zone of the creek. Within the recruitment zone, 11 pieces were dead or perched for recruitment while 68 were live trees (Table 2). The majority (87.5%) of the LWD surveyed within the reach fell within the 1-2 ft diameter class (Table 3). No large debris jams or notable wood features were observed within the surveyed reach segments on GL02.

GL05

Reach GL05 begins where Roderick Road crosses Gales Creek and extends upstream approximately 1000 ft (Figure 4). Habitat types within GL05 include riffles, glides and pools with a mean gradient of 2% (Figure 5).

The air temperature and water temperature in GL05 were 9 °C and 11 °C, respectively. On average, GL05 had 25.4 pieces LWD per 200-ft reach. One hundred twenty-seven pieces of qualifying wood were observed within the survey area, with 13 pieces observed within the bankfull width of the Gales Creek. The remaining 114 pieces were observed within the recruitment zone. Of these pieces for potential introduction, eight were dead or perched for recruitment; 106 were live trees (Table 2). The majority (89.8%) of the LWD surveyed within the reach fell into the 1-2 ft diameter class (Table 3). Two large debris jams were observed within the survey segments (Figures 4 and 6). The jams contained five and four pieces of qualifying wood and distinguished no habitat changes (Table 4).

GL06

Reach GL06 begins 900 ft downstream of the Roderick Road crossing of Gales Creek and extends upstream, ending at this crossing (Figure 4). Habitat types encountered included glides and pools with a mean gradient of 1% (Figure 7).

The air temperature and water temperature were 5.5 °C and 11 °C, respectively. On average, GL06 had 16.0 pieces LWD per 200-ft reach. A total of 72 pieces of qualifying wood were observed during the survey, with five pieces observed within bankfull width of the stream. The remaining 67 pieces were observed within the recruitment zone outside of either bankfull of the creek. Of these pieces for potential introduction, nine were dead or perched for recruitment while the remaining 58 were live trees (Table 2). The majority (59.7%) of the LWD surveyed within the reach sized within the 1-2 ft diameter class (Table 3). One large debris jam was observed within the survey segments (Figures 4 and 8). This debris jam contained three pieces of qualifying wood and marked a change in habitat type from pool above the jam to riffle below (Table 4).

GL08

Reach GL08 begins approximately 2,500 ft above the Springtown Road crossing and extends upstream 1,600 ft (Figure 9). Habitat types in GL08 include riffles, glides and pools with a mean gradient of 1% (Figure 10).

The air temperature and water temperature were 18 °C and 15 °C, respectively. On average, GL08 had 12.4 pieces LWD per 200-ft reach. Sixty-two pieces of qualifying wood were observed within the survey; four of these pieces were lying within the stream’s bankfull width. The remaining 58 pieces were observed within the recruitment zone on either bank. Within the recruitment zone, twelve pieces of LWD were dead or perched for recruitment. Forty-six trees were live (Table 2). The majority (85.5%) of the LWD surveyed within the reach sized within the 1-2 ft diameter class (Table 3). One large debris jam, containing four pieces of qualifying wood, and two beaver dams were observed within the survey segments (Figures 9 and 11). The beaver dams contained no qualifying wood pieces, but marked changes from pool to riffle habitat types (Figure 11).

GL09

Reach GL09 begins approximately 930 ft above the Springtown Road crossing of Gales Creek and extends upstream 1,700 ft (Figure 9). Habitat types in GL09 include riffles, glides and pools with a mean gradient of 1% (Figure 12).

On the survey date, the air temperature and water temperature at GL09 were 18 °C and 15 °C, respectively. On average, GL09 had 9.8 pieces LWD per 200 ft reach. Of the fifty-four pieces of qualifying wood observed within GL09, 11 pieces were within the stream’s bankfull width. The remaining 43 pieces were observed within the recruitment zone on either side of the creek. Six pieces within the recruitment zone were dead or perched for recruitment, while 37 pieces were live (Table 2). The majority (83.3%) of the LWD surveyed within the reach sized within the 1-2 ft diameter class (Table 3). One large debris jam was observed within the survey segments (Figures 9 and 13). This jam contained five pieces of qualifying wood, and marked no change in habitat type (Table 4).