- 5.7 is the water body substantially changed in character due to physical alterations by human activity (step 6)? provisional identification of hmwb

Provisional identification of HMWB
If it is likely that the water body will fail to achieve good ecological status due to hydromorphological changes then a range of options exist for objective setting. In some cases, restoration measures can be taken before 2015, which will allow the water body to reach GES. In other circumstances, an extension of the deadline by the application of the Article 4(4) derogation will allow the water body to achieve GES later. [15] Clearly, less stringent environmental objectives can also be set if an Article 4(5) derogation is appropriate. These approaches will be required in those circumstances where a water body is subject to significant changes in hydromorphology but is not substantially changed in character.

If a water body is to be provisionally identified as heavily modified (Examples in the toolbox) the following criteria apply:

1.
      The failure to achieve good status results from physical alterations to the hydromorphological characteristics of a water body. It must not be due to other impacts, such as physico-chemical impacts (pollution);

2.
      The water body must be substantially changed in character. This is the case when there is a major change in the appearance of the water body. It is clearly a partly subjective decision as to whether a water body is (a) only significantly changed in character (e.g. water abstraction without morphological alterations) or (b) substantially changed in character when provisional identification as HMWB may be appropriate (e.g. long-term hydromorphological changes caused by a weir). Both may be likely not to achieve GES. However, the following considerations should be borne in mind:

·
   When visiting a water body that is substantially changed in character, it should be very obvious that the water body is substantially changed from its natural condition;

·
   The change in character must be extensive/widespread or profound. Typically this should involve substantial change to both the hydrology and morphology of the water body;

·
   The change in character must be permanent and not temporary or intermittent;

·
   Many alterations to the hydrological characteristics of water bodies, such as abstractions and discharges, are not associated with morphological changes, and may therefore often be easily reversible, temporary or short-term. Consequently, such alterations would not constitute substantial changes in the character of water bodies and hence the application of HMWB designation would not be considered;

·
   The modification must be consistent with the scale of change that results from the activities listed in Article 4(3)(a): a canalised river, a harbour, a river constrained for flood protection or a dammed river or lake.

3.
      The substantial change in character must be the result of the specified uses. It must have been created by uses listed in Article 4(3) or uses which represent equally important sustainable human development activities (either singly or in combination).

In Table 1 , an overview of the main specified uses and the connected physical alterations and impacts on hydromorphology as well as on biology is given. A more extensive list of physical alterations and impacts on hydromorphology and biology can be found in the HMWB synthesis report (Hansen et al., 2002).

Specified Uses	Naviga­tion	Flood protection	Hydro­power generation	Agriculture/ Forestry/ Fish farms	Water supply	Recreation	Urbani­sation [16]
Physical Alterations (pressures)
Dams & weirs	X	X	X	X	X	X
Channel maintenance/dredging/ removal of material	X	X	X	X		X
Shipping channels	X
Channelisation/straightening	X	X	X	X	X		X
Bank reinforcement/fixation/ embankments	X	X	X		X		X
Land drainage				X			X
Land claim				X			X
Creation of back waters through embankments	X					X	X
Impacts on hydromorphology and biology
Disruption in river continuum & sediment transport	X	X	X	X	X	X
Change in river profile	X	X	X	X			X
Detachment of ox-bow lakes/wetlands	X	X	X	X	X		X
Restriction/Loss of flood plains		X	X				X
Low/reduced flows			X	X	X
Direct mechanical damage to fauna/flora	X		X			X
Artificial discharge regime		X	X	X	X
Change in groundwater level			X	X			X
Soil erosion/silting	X		X	X			X

If a water body is not designated and it becomes apparent later on that it probably is heavily modified, provisional identification as HMWB and application of the designation tests is still possible after 2004. Similarly if a water body is provisionally identified as HMWB, Member States do not have to complete designation. They can at any time consider it as a non-heavily modified water body and set appropriate objectives under Article 4(1)(a)(ii), 4(4) or 4(5).

5.7.1 Scope, scale and extent of provisional identification

Within the provisional HMWB identification, the scale, scope and extent of water body identification should be considered. It may be necessary to adapt the boundaries of the initially identified water bodies (step 1) according to the substantial changes in hydromorphology. More specifically, where the hydromorphogical changes do not coincide with the boundaries of a surface water body, it may be appropriate to subdivide the water body in order to separate heavily modified stretches from the unaffected areas of the water body.

The following three examples may be helpful for the decision on whether to subdivide water bodies or not under different circumstances (Figure 3 - Figure 5 ):

· In Figure 3 , two physically altered areas cover a major percentage of the absolute length/area of the original water body (8 km out of 10 km). The water body is, to a large extent, impacted by the same pressure and it would therefore be suggested not to split the original water body, but to apply provisional HMWB identification to the whole water body;

· In Figure 4 , the original water body is modified by a physically altered area (6 km) covering a major percentage of the entire length/area of the original water body. In this case it would be recommended to split the original water body into two distinct water bodies (1a & 1b). Water body 1b, impacted by the physical alteration, would be provisionally identified as heavily modified. The water body 1a would be regarded as a natural water body;

· In Figure 5 , a series of small physically altered areas each covering < 1 km are present at a small stretch of the entire water body length. Here the question occurs, whether those < 1 km stretches should be identified as distinct water bodies and be provisionally identified as HMWB, or whether the overall impact is low and therefore the whole water body should be regarded as a natural water body. It is suggested not to split the water body and regard the entire water body as natural.




Figure 3:
          Example 1, no subdivision of the water body




Figure 4:
          Example 2, subdivision of the water body




Figure 5:
          Example 3, no division of water body

Note: The provisional identification of HMWB refers to river stretches and not to the catchments or sub-catchments. In the three figures above the catchments are marked because it is difficult to only mark river stretches; the latter would be more appropriate.

Another important issue is that only water bodies which are substantially changed in character (due to physical alterations) themselves, may be provisionally identified as HMWB. If a physical alteration (e.g. dam) impacts the biological quality elements in the upstream part of a river system (for example fish migration is hindered), this upstream part may not be considered for provisional HMWB identification. If the GES cannot be achieved in this water body upstream of a physical alteration, the environmental objective may be less stringent.