IMPROVEMENTS IN OR RELATING TO MANHOLES AND THEIR USE FIELD OF INVENTION The present invention relates to manholes, their use and manufacture. BACKGROUND Manholes are used as access points to underground connections such as those for storm water and waste water. They have traditionally been either constructed or cast in place by the use of brick or concrete or manufactured off site by the use of concrete and then transported onto the site for installation. Such off site fabrication techniques either have the base of the manhole separate to that of the shaft or will have the two as an integral unit. Wherein the term "manhole" is used herein, it is to be appreciated it is not to be limiting in respect of the size of the opening provided, and inspection holes or non access providing inground chambers and the like may also be included. Casting manhole structures in concrete leads to a heavy, cumbersome and fragile construction. Depending upon the manhole size various sizes of heavy moving equipment must be used to locate the manhole in place and certainly such concrete constructions can not be moved into place by one or two personnel without heavy lifting equipment. The attachment of inlet pipes to such concretous construction requires the bashing or cutting of the concrete to facilitate attachment of an inlet pipe and thereafter cementing the inlet pipe back in place leading to a brittle joint which also requires considerable work in preparing and achieving. The cutting of length for the various installations of the concrete shaft again is difficult due to the fragile and tough nature of the concrete shaft material. Concrete typically also is not inherently water proof and requires additives or coatings to render it completely waterproof. The bases or prior art manhole structures typically are open and may be closed with a plug and generally are used for the connection of a number of inlet pipes at the base to one main primary conduit for the waste water or sewage. Typically these base constructions, should debris enter the manhole (either from the inlet or from above e.g. from a grate), are not self cleaning and suffer from blockage due to debris and build up. The manhole then becomes useless or impaired as a means of removing water and any waste materials. Plastic materials have been used in the construction of manhole structures however these have typically been of a segmented nature and are formed from complex pre-moulded shapes with their attendant expense. It is an object of the present invention to provide a manhole, its use and methods of manufacture which at least goes some way to overcoming the disadvantages of the prior art, or which will provide the public with a useful choice. BRIEF DESCRIPTION OF THE INVENTION In a first aspect the present invention may be said to broadly consist of a manhole for draining storm water, comprising or including, a hollow shaft including at least one inlet at or toward its upper end, and a tapered base engaged at the lower end of said hollow shaft, said tapered base tapered down away from said shaft, to at least one outlet wherein said base and hollow shaft provides a fluid connection in use between said at least one inlet, and said at least one outlet. Preferably said tapered base is a frusto-conical member or truncated cone. Preferably said tapered base is a square, triangular or other polygonal shape tapering base. Preferably said shaft has at least one annular reinforcing rib about its periphery, whether internally or externally located. Preferably a fluid conduit connects to said inlet through a wall of said shaft. Preferably said at least one inlet is connected or connectable by said fluid conduit to deliver storm water at a tangent into said shaft. Preferably said at least one inlet covered by or similar at the top of said hollow shaft and said grating is substantially at ground level. Preferably said outlet, in use, leaves said apex substantially parallel to the axis of said tapering base. Preferably said axes of said hollow shaft and said tapered base are parallel and vertically oriented (and preferably co-axial). Preferably said shaft is of a thermoplastics material. Preferably said base is of a thermoplastics material. Preferably said base is formed from a developed fiat sheet of plastics material. Alternatively said base may be manufactured by moulding or forming of a plastics material. Preferably said a pipe connected to said at least one outlet intrudes or projects at least partway into said tapering base. In a second aspect the present invention consists in a method of removing waste water wherein an outlet pipe exits vertically from an outwardly directed tapering base of said manhole, when in a vertical orientation, and at least one inlet pipe is tangentially connected to a wall or walls of the shaft of said manhole so that the influx of fluid from said inlet pipe aids in creating a swirling flow about the axis of said shaft at least on said tapering base to aid in removal of any debris present, down and toward said outlet. Preferably said swirling flow aids in removal of said debris down to and out of said outlet. Preferably said outlet pipe is substantially flush with the lowest point on said tapering base. Alternatively said outlet pipe intrudes a distance into said manhole, to aid in trapping debris and or water to a desired level. Preferably said manhole is a manhole as herein described with or without reference to the accompanying drawings. In a third aspect the present invention consists in a manhole as herein described used in a method as herein described with reference to any one or more of accompanying drawings . In a fourth aspect the present invention consists in the use of a manhole as herein before described with reference to any one or more of accompanying drawings. In a fifth aspect the present invention consists in a method of manufacture of a manhole comprising the steps of providing a hollow shaft and integrally joining at one end to this a tapering base whose apex is outwardly directed. Preferably said hollow shaft and said tapering base are of a thermoplastics material. Preferably said shaft is joined to said tapering base by plastics welding, such as ultrasonic welding, or heating, solvent attachment, adhesive attachment or other plastic to plastic joining techniques. Preferably there is the ability to form an outlet in said tapering base on or towards the tapering base apex. Preferably said shaft has one of more integral reinforcing rings about its periphery. Preferably said tapering base is formed with and outlet aperture. Alternatively said base is not formed with an outlet aperture, such aperture to formed during or immediately prior to installation or assembly. Preferably said tapering base is formed by development of a flat sheet. Alternatively said tapering base is formed by moulding, forming or other forming techniques. Preferably said shaft is cut to length for a particular manhole installation required. In a sixth aspect the present invention consists in a manhole produced as a product of a method of manufacturing as herein described with reference to any one or more of accompanying drawings. In a seventh aspect the present invention consists in a method of manufacturing as herein before described with reference to any one or more of accompanying drawings. In an eighth aspect the present invention consists method of installing a manhole and its connection to a main water conduit ("primary conduit") wherein said manhole is located upstream of its connection to said primary conduit, said connection between said manhole and primary conduit established by a secondary conduit. Preferably secondary connection is a flexible pipe able to be divided around existing utilities between said obstacles between said manhole and said primary conduit. Preferably there are tertiary conduits between said manhole and locations requiring water removal. Preferably locations are residences or businesses. Preferably water removal is waste water. Preferably the water is sewage. In a ninth aspect the present invention consists in a manhole as herein described with reference to any one or more of the accompanying drawings. In a tenth aspect the present invention consists in a tapering base for use in a manhole as herein before described. In a eleventh aspect the present invention consists in a hollow shaft for use in a manhole as herein before described In a twelfth aspect the present invention consists method of installing a manhole of the present invention as here in described. The term 'comprising' as used in this specification and claims means 'consisting at least in part of, that is to say when interpreting independent claims including that term, at least those features prefaced by that term in each claim will need to be present but other features can also be present. This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the present invention will now be described with reference to the accompanying drawings Figure 1 is a perspective view of the manhole showing the shaft and reinforcing ribs and tapering base, the tapering base attached to the hollow plastic shaft, Figure 2A shows the tapering base prior to its attachment to the into a shaft, and Figure 2B shows one method of producing the tapering base by development from a flat sheet, Figure 3 shows the attachment of an outlet pipe to the apex of the tapering base, Figure 4 shows in perspective view looking from above down towards the tapering base showing the attachment of a number of inlet pipes and the resulting swirling flow that can be developed by tangential arrangement of the inlet pipes, such swirling flow or flow that results moving down and towards the outlet pipe, Figure 5 shows the manhole in cross-section with the attached base showing the intrusion of differing height of the outlet pipe and the wall attachment of the inlet pipes, Figure 5A shows a similar view to that of Figure 5 whereby the outlet pipe 5 does not intrude into the interior of the manhole and thus is substantially flush with a tapering base to allow sluicing or removal of any debris build up, Figure 6 shows in plan view the arrangement of a manhole in connection to the primary conduit via secondary conduit, the location of the manhole being upstream of the primary/secondary connection relative to the flow of the primary conduit, and tertiary conduits branching out from the manhole as inlet pipes, and Figure 7 shows a horizontal cross-section through the ground into which a manhole has been installed showing the connection of an inlet pipe, connection of an outlet pipe and the arbituary path of the outlet pipe to avoid existing utilities, to its connection with the primary conduit e.g. the waste water or sewer line, and Figure 8 shows various polygonal forms of tapered bases. DETAILED DESCRIPTION OF THE INVENTION With reference to Figures 1 through 8 there is shown a manhole and method of its use and construction in accordance with the present invention. The manhole 1 may consist of a shaft 2 which is of a hollow plastics construction. The shaft has peripheral walls for attachment of one or more inlets 4. Preferably about the periphery of the shaft are reinforcing ribs 2 which are perpendicular to the axial direction of the shaft. Such ribs for a given shaft wall thickness increase the rigidity of and compression of the shaft and resulting manhole structure. The ribs may be on an internal or external wall of said shaft. The shaft may be manufactured from a thermoplastics material and may be manufactured by rotor moulding, moulding in general or by development from a flat sheet so desired. In a preferred embodiment, the shaft may be cut from a length of moulded thermo-plastic material. The length is cut to match the desired installation length. Alternatively set lengths of shaft may be provided and a shaft length is selected for a particular installation application. The shaft has a central axis 22. The shaft 2 has provided, at its lower most end, a (preferably by full engagement) tapered base 3 which is preferably a conical or semi-conical shape. It is generally of a tapered shape. The apex 3A is outwardly directed from the interior of the shaft and resulting manhole to form a lowest point of the manhole assembly when installed. The tapering base may be manufactured by a number of differing methods. For example the tapered base may be formed from a base development 14 from a flat sheet of material. Such a tapered base development is then folded up into a tapering base 3 thus formed to hold the debased development in their conical shape. The base outlet 3B may either be formed after the tapering base 3 has been constructed e.g. by the cutting off of a smaller cone section (e.g. the apex) to reveal an outlet of desired size or alternatively may be intentionally formed e.g. via the development shown in 2B to be of a particular side upon forming of the tapering base. Other methods for manufacture of the tapering base are casting or moulding to the desired form or blow moulding to the desired form or any other such technique known in the art for manufacturing a simple three dimensional shape from a plastics material. The tapered base 3 has a base axis 23. The tapered base as shown is preferably conical in form. However any form such as triangular 24, square or may sided polygonal form 26 may be used. The connection point of these with the shaft may be circular and thus transition to the polygonal form, on the hollow shaft 2, may itself be of polygonal form to match. The material of preferred choice for construction of the shaft and tapering base is a thermoplastics material as this facilitates easy cutting and shaping of the materials and also allows for the use of plastic welding techniques and/or solvent adhesive methods for joining of the tapering base to the shaft via a shaft to base join 12. Such joining of the base to the conical shaft may be achieved off site such that a ready assembled manhole is supplyable or if so desired may be fabricated onsite with the simple techniques described above. Indeed lengths of shaft material and various bases may be supplied onsite and used as required for the varying installation applications. The shaft central axis 22 and base axis 23 are preferably co-axial, when assembled on located together. When located in the ground the manhole, preferably has the axes 23, 24 vertically oriented. The base outlet 3B at the apex 3A of the tapering base 3 may, as described, be formed by cutting of a cone from the base to form the outlet size desired. Additionally there may be marked graduations about the tapering base to indicate where incision should be made to form outlets of varying sizes. Additionally also the outlet base may have different markings for different shapes other than that of circular outlets. Additionally there may be provision for one or more outlets in the tapering base. The outlet pipe 5 is attached to the base outlet 3B of the tapering base 3. The joining of the outlet pipe to the tapering base may be achieved by means known in the art such as "o" rings and similar joining systems, on there may be direct adhering or welding to the plastic material of the tapering base, particularly when the outlet pipe outself is also of a plastics construction. Preferably fluid conduits as inlet pipe(s) 4 are attached to the walls 2A at the upper end of the shaft. In the preferred embodiment the inlet pipes are attached tangentially to the shaft so that when waste water flows into the manhole 1 from the inlets there can be developed a swirling flow 9. The development of such a swirling flow is not always required, however during periods of heavy use it is a flow that is likely to be developed within the manhole structure. The attachment of the inlets to the pipe or pipes walls 2B of the shaft of the manhole 1 can be affected by methods known in the art such as "o" rings sealing and/or plastics welding or adhesive attachment. Due to the tangential nature of the preferred attachment of the inlets pipes 4 to the shaft 2 there will be developed in the shaft walls 2A apertures of a non circular cross-section 19. The use of plastics materials for the inlets and shaft is ideally suited to such non standard aperture creation and joining as plastic welding or adhesive techniques may be used to simply effect the joining of the two. Present also may be a grate 27 covering the inlet to the hollow shaft. The grate 27 lies substantially at ground so that waste or storm water 28 can flow into the manhole 1. The manhole alternatively may sit entirely below ground to act as a chamber with only inlets 4 and outlets 5. Typical access hatches known as manhole or access covers may also be present to allow access. The outlet pipe 5 may sit flush with the bottom of the tapering base 3 or alternatively may intrude into the interior of the manhole and have a varying outlet pipe intrusion length therein. Such intrusion may serve to prevent debris from moving down into the primary conduit where this is not desirable and as such will form a trap between the outlet pipe aperture 20 and the tapering base 3. Periodical servicing of the manhole is therefore able to remove the collected debris where it is desirable to prevent such debris from flowing down into the primary conduit and or sewerage/waste water systems. Additionally also such intrusion into the interior can form a water trap where it is desirable to have a level of fluid above any inlets into the manhole where it is desirable to control odour or similar. Such a trap will create a siphon in the bottom which will aid in presenting the stirring up of silt and debris that have settled. The intrusion of the pipe can also serve as a measure of silt build up over time when checking, e.g. during periodic maintenance. The tangential attachment of the inlet pipes 4 to the manhole 1 will create as stated in times of heavy flow a swirling flow within the confines of the manhole 1. Such swirling flow is beneficial in conjunction with the tapering base whereby when the outlet pipe 5 is flush with the bottom of the tapering base 3 the swirling flow developed will serve to at least partially clean and remove any substantial debris build up on the walls and base of the manhole and will direct such remove debris or floating debris in the fluids downwards towards the tapering base and thus aid in flushing or sleighing the debris out the outlet pipe 5. In such a way the manhole is self cleaning and the build up of debris, in such a confϊguration, is prevented from occurring and thus blockage of the manhole system and its attached pipes is greatly reduced. A method of use of the manhole involves the location of the manhole at least in part substantially under ground or with the top end of the manhole flush with the ground level and the preferable connection thereto of tertiary conduits 8 (which are also the general inlet pipes 4). Such tertiary connections are to distributed waste water sites such as the sewer connection for a house or business or residence or the waste water connection of such also. The manhole connection is then effected via a secondary connection via a secondary conduit 7 (which is also the outlet pipe 5) down to a primary conduit 6. The location of the manhole is such that it is upstream of the connection of the secondary conduit 7 to the primary conduits 6, in relation to the main conduit flow 15. The use of a plastics material for the secondary conduit or outlet pipe 7 and 5 respectfully allows the secondary conduit to be guided round existing utilities 18 which may be in place under ground. Such guiding around may be achieved by techniques known in the art for trenchless excavation or alternatively the utilities and direction for the secondary conduit may be exposed by a trench and the secondary conduit laid accordingly. Provided there is an overall fall from the tapering base 3 to the primary conduit 6 then the effect of moving of fluid and/or debris down the secondary conduit will be achieved. The invention has the advantage that a light weight recyclable unit with lower maintenance requirements can be placed to more optimally serve a number of tertiary connections. Wherein the prior art 1 manhole may be used for each tertiary connection, due to site restrictions, or connection to primary or secondary lines, the present invention allows more convenient placing and thus fewer manholes are required. As fewer manholes are required then fewer holes are required to be dug and less waste material in the form of removed earth and dirt needs to be disposed of. This results in lower costs for construction in that a) there are fewer installations of a manhole required and also b) less material is required to be removed from the construction site or installation site of such in assembly. The vertical orientation of the outlet pipe also allows for the easy and effective maintenance of the manhole and also its outlet connection. The opening of the lid of the manhole easily exposes the vertically opening outlet pipe to a user such that a camera can be simply dropped down into the outlet pipe and/or apparatus to scour or clean the pipe can be simply inserted into the outlet pipe. Together with a swirling action the amount of time between maintenance visits may be extended as the debris and similar has been sluiced away in a situation where the outlet pipe is substantially flush with tapering base. In the preferred embodiment the depth of the manhole is approximately 1.5 metres so that a user of the manhole does not need to descend into the manhole for servicing etc as all inlets and outlets are easily within reach of either the user or any apparatus the user may need to utilise within the manhole. Additional also a similar construction manhole may be inverted on top of the manhole to form a restricted entry cover being that the entry may only be approximately the same size as the outlet to the manhole. In this way the undesirable entry of personnel into the manhole can be prevented whilst still allowing easy access for maintenance and/or camera work within the manholes structure and surrounding pipe work. The utility structure described within the specification may equally find use for holding tanks, or storm water tanks or sceptic tanks in such fall within the scope of the specification when constructed in a method or manner taught within the specification.