DRY REACH MONITORING PROTOCOLS

updated December 2010

INTRODUCTION

A “dry reach” is a continuous length of creekbed that has no contiguous surface water flow but may have isolated pools. In Sonoma Creek and its tributaries, dry reaches are naturallyseasonally associated with alluvial fans and other coarse stream substrates where surface water goes under the creekbed and emerges again downstream. Groundwater feeds our creeksstream flow in the summer (called base flow), and the level of shallow groundwater is a large determinant in the level of summer surface flows.. NTo an extent, native species are adapted to these naturallyseasonally occurring conditions, but an increase in the length and number of Dry reach monitoring measures the extent of these reaches at the beginning and end of the summer (dry) season. Ddry reaches act results as barriers to fish movement and feeding and thus are an important factor in evaluating in reduction and impairment of summer aquatic habitat, which is considered a limiting factor for steelhead in SonomaValley streams.

Collecting information on the elongation changes in extent of these dry reaches over time,allows us to study informs the seasonal relationship between groundwater level and stream flow as well as allows evaluateion of long-term trends from year to year. Dry reach monitoring measures the extent of these reaches, and the data is evaluated together with other information to assess the degree of impairment by human-caused factors such as pumping and watershed hydromodification. SonomaEcologyCenter has been conducting dry reach monitoring since 2003. See for access to the data and all supporting materials.

FUNCTIONAL DEFINITION OF A DRY REACH

(Check LFA for a reference; Lisa told me this). A “dry reach” is a stretch of creekbed that has no contiguous surface flow. Dry reaches can have isolated pools.

PROTOCOLS

When funding and staff are available, we SEC recommends the following schedule for dry reach monitoring on a select group of streams with steelhead nursery habitat:

  1. When dry reaches first appear in the late spring, survey their upstream and downstream limits and record these using GPS (c. early June[rl1]).
  1. Before cooler weather returns and base flow begins to rise, survey and record the farthest upstream and downstream limits of dry reaches again (c. late September).

When funding and staff are limited, we SEC suggests adapting the monitoring in one or more of the following ways:

  1. Monitor once a year at the end of the dry season (c. late September)
  1. Using Use visual surveys from access points (rather than walking the channels)

Preliminary Steps: Preparation

See for survey site maps, landowner contact info, and previous years’ data

  1. Starting with previous year’s list of landowners, make landowner contacts, acquire permissions, and update contacts as necessary.
  1. Review protocols, previous year’s data, and survey sites. Contact SEC staff who have knowledge about dry reach monitoring.
  1. Contact Chris Farrar and the hydrological team at USGS about coordinating with their seepage runs.
  1. Set up GIS files for current year (what standard fields do we want?).using templates provided In Knowledge Base.
  1. Ready equipment:
  2. GPS unit (handheld recreational OKGarmin),
  3. pPrint- out of site maps and directions and, data sheets,
  4. notebook, cClipboard, pencils, camera, rubber boots.
  1. Plan routes: The idea is to fFind the upstream and downstream ends of dry reaches and make sure the reach is really dry. Start upstream and work down, starting with the location that is likely to be above the beginning of the dry reach. Once you’ve found the beginning of the flowing section, you can observe an additional point or two to make sure the dry reach has ended and then stop.

Field Work

  1. Using the strategy mentioned above, record observation locations with GPS and one of the following attributes on the data sheet:
  2. : Wet = flowing waterFlowing = visible water movement
  3. I. Stagnant = isolated pools, no visible flow (this designation under consideration).
  4. , no flow. Dry = dry streambed, no visible water or no flow.
  5. Transition = change from of the above conditions to another.
  1. IMPORTANT: Make observations at access points and walk stream bed only when necessary to attempt to narrow down location of ends of the dry reach or confirm status of the creekbed. With experience or by talking with people who are familiar with these reaches, you will know when it is unnecessary to walk the bed because it is known to be dry down to the next access point. Walk in streambeds only where it is safe to do so, being aware of hazards such as homeless encampments, heavy vegetation, and wildlife.

If wet at access point: walk upstream and downstream (how far?). Record upstream and downstream points, record as wet. If a dry reach is found, go to #2.

1.If dry at access point, walk upstream until you find flowing water, or are unable to continue due to property boundaries.

  1. Record location with GPS. If unable to get aAs a back-up totaking GPS readings, estimate and mark location on a map and record any visible landmarks.
  1. Record locations of any significant (deep, fish-bearing) pools (If time allows).

2.Fill out data sheet. Wet = flowing water. Stagnant = isolated pools, no flow. Dry = dry streambed, no flow.

  1. TaAt observationpoints, take a photograph looking upstream and another looking downstream. (Tie a yellow ribbon round the old oak tree for next year’s survey?).

3.Repeat these steps, going downstream.

  1. If prevented from completing a dry reach survey due to property boundaries, try to find another access point (e.g., road crossing, accessible property etc.) to further assess the limits of the dry reach.

Notes from Deanne: Having done this field work, I advise an approach based first on point observations and only walking the stream when necessary.

Follow-upUp: Data mManagement and eEvaluation

  1. Download GPS point data into GIS.
  1. Draw polylines to connect points for each reach.
  1. Input information from data sheets into attribute tables.
  1. Integrate analysis of data with previous years’ Excel tables and text.
  1. File hard copy field notes in Dry Reach Management File in M.U.D. lab.

[rl1]Hi Arthur, isn’t it usually in May? Just checking.