Bond Brook "Stream Team"

Training & Data Collection

Tuesday August 2nd 2005

Hosts & Trainers:

Maine DEP, Kennebec Valley Trout Unlimited, Kennebec County Soil & Water Conservation District

Attendees:

Summary:

At least 16 volunteers participated in the classroom training and stream walks. The one-day program was successful in meeting our objectives of introducing the volunteers to the Stream Team protocol and collecting data on four sections of stream in the lower Bond Brook watershed. Dave Sherwood of the Kennebec Journal wrote an article published the next day. The completed survey forms were collected by DEP and KCSWCD to be used by DEP once the electronic database is ready for data entry.

The brief powerpoint presentation by Mary Ellen Dennis of DEP went over all the major concepts of the Stream Team protocol and the individual questions on the form. Reach delineation and geomorphology were touched on, with emphasis placed on answering questions in the field.  The group was divided into four groups according to the difficulty of walking the sections, which ranged from quarter-mile to half-mile long. Each of the four sections demonstrated a great deal of variety in terms of terrain, riparian area and level of disturbance. Individual reaches were identified during the walks. A brief insect collection demo was performed at the completion of the walks and picnic. A few volunteers and staff met by car to visit another site near the Marketplace development, where there are two small waterfalls on exposed ledge.

This public education activity of the 319 grant generated publicity for the brook and should help build a constituency for stream stewardship and management. With the recent award of the Bond Brook management plan grant to the local Trout Unlimited chapter, there is a greater chance of maintaining Stream Team volunteers and collecting the data in an organized way. Identification of past BMPs and their functionality is one of the tasks of this management plan.

Highlights of the observations:

Group 1 (Airport dropoff upstream on unnamed tributary to Old Winthrop Rd)

Multiple (as many as 10) reaches in this section, caused by boulder fields almost completely burying stream, interspersed by open, meadow areas. Several beaver dams creating some deep ponding in uppermost reaches. Boulder fields are serving to slow and cool flow, sediments drop out. Pools in open sun are not completely turbid, some of the open stretches have pondweed growing. Small black-nosed dace are everywhere. Surveyors flags are prevalent in uppermost reaches (near I-95) marking channel edge but not floodplain. Riparian varies from mixed hardwood/hemlock to all hemlock in some steeper areas. The stream is channelized where it passes immediately next to I-95. The stream is at its coldest (18 C) upstream of the I-95 ditching, again in a bouldery, shaded area. While several stretches show signs of overflowing and bank cutting in past high flow, the sedimentation in the stream appears to be from upstream sources rather than stream banks - except perhaps in the case of the channeled stream next to the steep I-95 bank. There is very little trash or direct human impact until the upper section nearest I-95. The most obvious sign of disturbance is the siltation throughout.

Group 2 (Airport dropoff downstream on unnamed tributary to Bond Brook Rd.)

(abbreviated from C. Bohlen’s full report)

The stream segment we walked was highly variable.  Those of us on the stream walk felt it made little sense to treat the entire segment as a single reach. 

Reach 1:  Road down to top of steep boulder field: Channel is briefly well defined before entering the backwater from a beaver dam.  Perhaps 10-15 feet wide (not measured).  Floodplain present on downstream left bank, steep hillside downstream right.  Floodplain harbors wetland vegetation.  probably still well connected to stream channel, at least during larger floods.  Channel banks largely fine sediment, but channel contains some boulders and lots of woody debris. Below beaver dam, channel is slightly incised; some evidence of erosion on both banks, more on outside edge of meander bend.  But large floodplain is present, low enough for access during significant floods. One more (significantly smaller) beaver dam.  Woody debris still present, although mostly smaller than above. Pass under the line of lights for the runway approach.  Tree canopy removed some bank erosion on steep (downstream right) bank. Sediment input from steep, sparsely vegetated slope. Increasing abundance of large boulders.  Channel bottom mostly sands and fines.  Channel largely locked into place by numerous large boulders.  Clear sediment line well above (18 inches) current water level showing height of recent (spring?) floods.

Reach 2:  Boulder field: Channel looses almost all sense of a channel.  Water flowing across a nearly 30 m wide band of boulders. Area forested, all well shaded. Water is mostly flowing under and among medium to large (0.25 m to 0.5m) boulders.  Cobbles and gravel in protected pockets behind a few boulders suggest some sediment transport occurs through this reach during high flows. Little sand, no fines to speak of.  Small numbers of caddisfly cases on cobbles between boulders. Low insect diversity. Channel briefly exists as two separate identifiable channels, which rejoin among more widely scattered boulders

Reach 3:  From Boulder Field to Gravel Pits: Channel  enters a more open floodplain, dominated by shrubs, grasses and sedges.  Large boulders and somewhat scattered woody debris help define channel form. Channel bed material varies from sand through small cobbles, with pools mostly associated with boulders (and some woody debris). Large (4-5 inch) blacknosed dace are abundant in some of the pools. Leopard frog observed adjacent to stream.  Water temperature in pool here, 69ºF.  Slightly farther downstream, the boulders become less abundant, and we are into a gently meandering channel through a narrow floodplain (because the channel is narrow, we still have an embeddedness ratio (Flood prone width/Channel width) over 2.5.  Larger cobbles show only slight (25% or less) embeddedness.  Stream bottom materials clearly sorted into finer materials (silts) in pools and coarser materials (gravels and cobbles) in short riffles. Clays (Presumscot formation?) are exposed in the thalweg in some areas, mostly visible in runs.  Meander wavelength is about 5 channel widths, but meander amplitude is very small.  Pools are mostly shallow (12 to 18 inches; only occasionally deeper) associated with large boulders and woody debris.  Dace continue to be abundant, although smaller in the (mostly) shallower pools.  Channel shows some evidence of incision.  Lots of dear tracks on silts on point bars and banks.

An abrupt right hand turn in the channel perhaps 50m upstream of the Dragon Cement Gravel pits creates a deep (2.5 ft or more) pool under an undercut bank supported by the roots of a shrub or small tree Water temperature about 70ºF.  The right hand turn brings us to a deeply incised channel cut into a still grass and sedge-dominated “floodplain-like” deposit of sediment. The channel is incised more than 6 feet below the floodplain elevation here. The incision is narrow, only slightly wider than the channel itself. The banks are mostly fine sediment, with little vegetation, and some evidence or recent slumping, suggesting that the incision is ongoing.

Reach 5:  Through the Gravel Pits: Just below the confluence with the small tributary, the channel becomes narrowly confined between a high (50 ft) steep downstream left bank, and a lower (20 ft) berm on the right bank, probably of material pushed from the gravel pit years ago (it now supports moderate sized trees).  This narrow constriction between two steep banks characterizes most of the channel as it flows through the gravel pits.  Even where the stream does not impinge on a natural steep bank, the channel is confined between two banks that appear to have been formed by pushing materials from the gravel pit toward the stream.  The slopes are poorly sorted, contain many cobbles, and now support moderate sized (6-10 in DBH) trees and shrubs. As we walked through the gravel pit we saw lots of debris in the channel, mostly iron and steel.  Some was clearly identifiable and remains of rock sorters and other industrial equipment.  The culverts that permit access to both sides of the stream for gravel pit operations are in poor condition.   They are being bypassed by some of the stream’s flow, which threatens their long-term stability.  Flow through the culverts was very shallow (often less than an inch).  They clearly act as a barrier to movement of fish and other aquatic organisms.  They also appear to be nearing the end of their useful lives. Incised channel due to encroachment of gravel pit operations on the floodplain continues.  A trailer is located almost in the stream bed, and several slabs of cement/concrete are in the channel or embedded in the bank.  Several short sections of bank are armored with riprap. 

As we emerged from the narrow, confined channel reach, the stream opens up into a broader floodplain.  Bed materials shift somewhat towards finer materials, and we observe several small point bars suggesting the beginnings of a more geomorphically dynamic channel.  The channel runs up against the base of a high (30+ ft) eroding bank on downstream left bank.  Snow fence is halfway down the face of the scarp, and an old truck is parked at its top, where it appears likely to fall in the next few years.

This is a clear source of sediment to the stream, and a short (40 m section of stream downstream is choked with fine sediments.  A beaver dam about 40m downstream of the bank has trapped several feet of fine sediment.  The channel immediately downstream of the dam appears to be in better shape, with a cobble bottom with relatively low embeddedness. Just below the beaver dam, we passed a small farm with a few livestock (cattle; we think horses also) who have access to the floodplain, but are fenced out of the stream itself. The remainder of the walk to the confluence was over relatively straight stream dominated by cobble, low embeddedness, generally little more to report.

Group 3 (Mt. Vernon Ave. ballfield upstream on Bond Brook to intersection of Mt Vernon & Bond Brook Rd)

This reach extends from the ball fields on Mt. Vernon Avenue to approximately where Bond Brook Road joins Mt. Vernon Avenue.  There is a tributary that crosses Bond Brook Road at the upper end that probably drains UMA.

The upper two thirds or more of this reach is quite nice with good habitat (lots of riffles and deep pools).  The lower part is still a fairly nice stretch with lots of pools and runs, but fewer riffles.  This lower part appears to be more impacted by development and urbanization.  It has fewer riffles probably due to indications that aggradation and widening is more evident here.  The reach as a whole is fairly uniform in terms of gradient, substrate etc. but it can perhaps be broken into two sections for geomorphology assessment.  The width averages about 25 feet with some wider sections and it is narrower in the upper end.  Gradient and stream velocity is moderate with many riffles, runs, and deep pools (except as noted above).  Substrate consists of high amounts of rubble, cobble, and sand with smaller amounts of boulder, gravel and silt/clay.  There is more sedimentation and deposition in the lower part.

Lots of fish of all sizes were observed with dace and bass being identified.  Temperature of 70°F or 21°C was measured at both ends of the reach.  Lots of algae and bugs (as well as good diversity) were observed indicating a healthy stream, although also probably fairly productive. 

The rapid geomorphic assessment indicates that the reach is responding to changes in watershed hydrology or sediment loading.  Evidence of aggradation was most prominent with 6 indicators noted; including bar formation, deposition and soft bed.   Four indicators of widening were noted including exposed roots, bank scour, leaning trees, and fracture lines along the top of the bank.  Planimetric form adjustment (3 indicators-islands, chutes, evolution of pool-riffle form) and degradation (2 indicators) were also present. 

 The riparian areas for the two sides of the reach are very different.  The right side is mostly wooded and undeveloped, but there are ATV trails that run along close to the stream and there is evidence that ATVs cross the stream.  Development is present close to the lower two-thirds of the left side.  In some areas development is close to the stream (50-75’), but most is set back further from the stream.  There is a buffer between development and the stream for most of the reach.  Exceptions include the ball fields where the floodplain is filled and it is cleared close to the stream.  There is only one site where there is lawn down to the stream-about a 75’ section that is also riprapped.  There are few places where development is close and the buffer is smaller. 

At the lawn site, a storm drain was noted.  There are a couple of small tributaries or drainage ways coming into the stream on the left side.

Group 4 (Mt. Vernon Ave. ballfield downstream on Bond Brook to waterfall)

The upper part of the reach was fairly "walkable" and a slight slope to it.  The lower half of the reach generally had deep water (> 2-3 ft in many places) and had fairly flat slopes, although there was a small "cascade" and a "waterfall" present in the lower half of this reach due to the exposure of ledge/bedrock in the channel.  Flows apparently can get quite high (and fast) in this section, as evidenced by leaf-packs trapped in tree branches > 5-6 ft from the channel bottom.  While there were some bedrock, boulders, cobbles, and gravels in the stream, the channel was dominated by fine sediments (sands, silts) and larger rocks generally were moderately-embedded (~ 50%).  This heavy presence of fine sediments may partially be due to contributions from watershed development, however it is likely that a significant portion is a result of natural geologic processes (i.e., this section possibly was under the ocean and subjected to deposition of marine sediments after the retreat of glaciers).  This would be worth confirming with local surficial geology and glacial history maps.  Generally, riparian vegetation cover on the banks was decent, although in many places the canopy was ~ 50% open.  This may have been a result of the width of the stream being > 4-5 meters in many places.  There was evidence of human encroachment and impact on the stream.  Some examples included an apartment complex encroaching on the stream corridor, with parking lot runoff, trash, yard (leaves) waste, and riprap evidently impacting one bank.  Also, at a section where a small cascade/waterfall (plus a short riffle) apparently was naturally present, human impacts were evident by the apparent dumping of large blocks of granite in the channel.  These may have been remnants of an old dam since some blocks were on the floodplain as well.  Also, some wood planks apparently had been placed in the channel at this site in an effort to pool up water for recreation (e.g., fishing, swimming, etc.).  At the second, lower waterfall, a fish weir was in place to assist with longitudinal movement through the stream.  It was difficult to imagine fish migration prior to the installation of this weir, although it may have been possible at high flows or in the absence of human manipulation of the stream corridor.  The rapid geomorphic assessment suggested that the stream may be responding to human disturbances in the watershed, with channel aggradation (sedimentation) [possibly natural in part] and channel widening being the most evident.  Planimetric form adjustment of the channel also seemed evident with some chute formation, evolution from pool-riffle form to plane bed form (long stretches of flat, sandy, uniform channel morphology for long distances in the lower half of the river), and may be in response to excessive human contributions of sediment and water due to urbanization of the watershed.  Other apparent impacts in this reach included 1) a powerline crossing, which periodically removes vegetation from the area and which may have weakened some stream banks and caused overwidening of the channel, and 2) what appears to have been a former reservoir behind an old (removed) dam near Route 27).  This reservoir was probably manmade and resulted in overwidening of the channel, which led to degraded stream habitat in this region (lots of fine sediments, lack of habitat structures like large woody debris, very slow flows, etc.).  Fish were observed in this reach, ranging from numerous minnows in certain sections, to what were believed to be a rapidly-swimming bass and brown trout (though no confirmation is available). 

Types of Questions Asked by the Trainees:

Identification of species (aquatic plants, fish)

Probability of fish passage during different flow levels

Geological & Ecological history: e.g., are old beaver ponds cause of standing dead wood? Why are some areas bouldered and others not?

Estimating depths and distances, flow

Assessing degree of siltation and algae content 

Next Steps:

The next step is to have individuals volunteer to be team leaders for the area and organize future stream walks and/or serve as a conduit for submitting data to DEP. [For the time being, Mary Ellen Dennis and George Viles will serve as volunteer coordinators].  KCSWCD can serve as a GIS service to provide maps and aerial photographs to the volunteers. High school environmental programs (Kents Hill and Cony) should be contacted to organize youth Stream Teams in the fall. The remaining steering committee meetings for the current 319 grant can also be used to help plan activities of the Stream Team. 

Attached: maps of the survey sections; photographs

 Photos from Group 2 (Airport dropoff downstream on unnamed tributary to Bond Brook Rd.)

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