Preliminary surveys of waterways are a process of getting to know your river. They involve library research, understanding topographic maps and aerial photographs (lots of fun that), as well as field trips to explore the general features of the waterway and learn more about the creatures that live in and around the waterway.
Not only are they enjoyable experiences, preliminary surveys are absolutely necessary to a good monitoring plan and other survey activities.
Before setting foot in the field, you need to prepare a river map. Use a topographic map(s) of the catchment area for strategic planning. (obtainable from Local Council or Institute of Geological & Nuclear Sciences).
Enquire at your nearest Lands Survey office or at your council to see if you can borrow or view aerial photographs of the area to compare to the topographic maps (Topographic maps are made from aerial photographs. Looked at in stereo, they are even better than flying over the terrain). Using these aids prepare your map and plan your research stations:
see where roads cross the water giving easy access for monitoring.
pinpoint where concentrations of people - or livestock - live along the waterway.
Work out where the wetlands and estuaries are (or were).
Identify the limits of the stream / river (where it starts to where it runs out to sea).
Identify the boundary of the water catchment (all the land that drains into stream).
Mark sites where water is drawn from river with a standard symbol to indicate size of withdrawal. Use a graded size of symbol or a number suffix on a 5 point scale.
Mark where effluent / pollutants enter the stream as piped flow, or as agricultural or horticultural run-off (hash land run-off areas on map).
Mark the extent of forested land in water catchment, including native forest, and exotic forest.
Highlight usage areas with boundary lines and distinct hashing or shading.
Mark the extent of tidal flow in estuaries.
Ask permission well in advance if you would like to enter private land to establish a survey station. Be sure the landowner knows why you are doing the survey and invite the landowner to attend the meetings of your monitoring group and perhaps become a member and help do the survey.
If the property is some distance away, write a letter explaining why you are monitoring. Be clear that the purpose is to improve the water quality of the whole river and not an attempt to discover if they are doing something wrong. The landowner may be concerned about public liability claims if you should have an accident while on their property. Be aware of the following courtesy considerations:
Volunteer safety must be a top priority for water monitoring groups. Safety considerations should include travel to and from the site, pier or bank stability, testing procedures and weather conditions.
Before getting involved
with complex sampling programmes and the recording and analysis
of data, start simple.
After selecting a variety
of easy access places from your map and visiting these sites
to check them out first, arrange to take a class or community
group trip to look at different sections of the river to identify
and record general impressions at each site.
What makes a stream
or river healthy or unhealthy ? Visit sites that are in natural
surroundings and sites in an area believed to be polluted. What
differences can the group identify quickly and easily in the two
places? How could these be measured?
Which areas have been
subject to human interference? What sorts of evidence can the
group detect that indicates human interference?
What is the vegetation
like along different stretches of the river banks? How would this
change the health of the river?
How are people using the river?
Against a chart of the following categories make brief one line comments for each site visited :
- Water flow
- Water colour
- General description (Broad, fast flowing river / narrow meandering creek)
- Natural floating debris (eg leaves, twigs)
- Oil films on surface
- Froth (from detergents)
- Rubbish and or scums along water's edge
- Dead fish seen floating
- Living fish seen swimming
- River birds swimming on / under water
- River birds feeding from water or water's edge
- Public use for sport
- Public use for recreation
- Source of pipes draining into stream
In a close up map (drawn as a series of maps showing the stream in numbered sections) identify:
Vegetation types alongside the main channel : e.g. Mangrove fringing forest, Marshland (salt meadow, rush marsh), Forested fringe (native or exotic), Agriculture, Horticulture, Mown parkland, None (roadway or other permanent hard surface).
Identify where banks are overhung by vegetation or open.(affects quantity and diversity of stream life)
At each site make a record under the following categories:
Large animals or sign* of animals seen alongside the waterway or on the water. Cattle, horses, sheep, deer, pigs. (These animals break down stream banks, eat shading vegetation and may pollute waterway with excessive amounts of dung.)
Rabbits, rats, possums, stoats, dogs, cats. (These animals eat bank vegetation or kill wildlife associated with stream and may foul banks or waterway
Birds: including water fowl (ducks, swans, coots, shags) swallows, kingfishers, waders (pukeko, herons). (Birds can be good biological indicators of water quality, reflecting presence of suitable food, shelter and nest sites.)
[* Sign = droppings, footprints, browsed vegetation, fur and feathers.]
Small animals (> 5mm)
Snails, crustaceans, insects (larvae). There are several techniques used to catch and observe these specimens.
Map bridges, piers, stormdrains, discharges, or other structures or facilities that have an impact on the waterway.
On the preliminary survey map, indicate places were long term monitoring stations might be set up. Show landmarks, bearings, roads, bridges or other key details so the stations can be relocated exactly in future.
Take a set of photographs of the stations to add to the base-line reference log book.