ST. CLAIR BEACH.

Evening Star, Issue 11724, 6 December 1901, Page 2

ST. CLAIR BEACH.

At last night's meeting of the Ocean Beach Domain Board the report of Mr J. Blair Mason on the conservation of the Ocean Beach Domain and the protection of St. Clair was submitted.. Its consideration was deferred. The report was exceedingly lengthy. Mr Vason acknowledged the receipt .of all re- ' fits and plans which the Board had re'■'ived on the subject .and which were reared to him for consideration. They were '••oai the following gentlemen : —Messrs G M. Barr, S. H. Mirams, E. R. Ussher, L. '•'. Reynolds (21, W. H. Huteheson (2), and I''. W. .Petre (2). We publish that portion dealing with * ; t. Clair and the beach and the sand flats to the north:— Restoration of the Beach at St. Clair.— With the exception of the portion opposite! St. Clair, no apprehension need exist as to ;he stability of the beach under prevailing conditions, in which the waves spend themselves gradually upon the sandy slopes, leaving in the aggregate more than they take away. - In the case of the frontage to St. Clair, this aggregate is evidently not sufficient to make up the loss from other causes, and the cruestitm becomes: Can the supply be increased from seaward? My own experience, and what is being done elsewhere, convince me that it can. The character of the works of any scheme one could conscientiously recommend would be such that, while offering a minimum resistance to the impact of the sea, they would intercept and arrest some portion of the water-borne drift in ite progress eastwards, causing it to work into the bight at St Clair and build up the foreshore. Groynes: To accomplish the above I would advocate the construction of a groyne or groynes, run out from the shore or toe of the Sandhills until the desired effect is obtained. The projection of such groyne just beynd the Forbury road towards the Central Battery would intercept portion of the drift that at present finds the shore further east, and distribute and pile up such drift along the shore to the westward of the groyne, .letty groyne: I am inclined to believe that one groyne would suffice to restore the beach at St. Clair. A good type would be that of a jetty, consisting of a row of piles, say, 10ft apart, with a parallel row, way,. 20ft apart, for staying purposes and to cany the truck for the pile-driver. The piles to be braced and waled or sheet-piled between. Heavy rubble or boulders, obtained as suggested by Mr Reynolds, from 1 lie boulder beach, could be lajd along the imter portion at a later date if' required. The distance out such a groyne would require to be taken would probably not be timber than into 3ft or 4ft at low water. It would be better, however, not to define iiny definite length of structure, but watch i he effect of each completed portion in building up the beach before extending it further. It is manifest that the accumulation of saud beyond what is needful to maintain the foreshore is not desirable at Sr. Clair, as a a pleasure resort, nor is it <U>-inible for other reasons that such groyne should extend beyond the depth I have mentioned. Any sand working into the bight through the agency of the groyne would in the earlier stages remain there, gradually raising the level of the beach, and enabling a roadway or esplanade wall to be constructed, flanked by a stable bank of wind. Experimental groyne: Extended observation leads me to believe that in fine weather there is sufficient influx of sand into the bight at St. Clair to warrant the placing of a groyne immediately west of Forbury road, as preliminary to the consideration of other proposed restorative works. Such groyne could be made of cribs, triangular in section, and filled with f he. stones of the old wall now lying on the beach. I anticipate that a length of 200 ft from the foot of the bank would be long • enough at first, and is estimated to cost £IOO. The success of a groyne at the place indicated would simplify the operations of the Board in dealing with the K>planude, and I would therefore urge that ii lie erected at an early date, to get the tn'\" .■-ni:ip;e of the summer season, and that iIOO be allocated for the purpose, ■Si.'ii- Walls.—lt is always desirable to maintain a sand beach as the first and best di feiiix' against the sea,, fostering its renoviirion by every known means. But under conditions where such is impossible a bulAvark or .wall of defence becomes an absolute necessity, whatever may be the consequence to the beach in front. The formation of a promenade or esplanade between the baths and Forbury road, essential to St. G'iair ao a v. atering-place and a likely boon to the community, is no s doubt a work to be included in. any complete improvement scheme. But the effect of the sea Avail of such esplanade on the maintenance of St. Clair Beach Avould, in my opinion, he injurious unless protected by groynes along its unsheltered portions. Without such protection the prevailing fetch of the sea, being more or less defietced by the wall (depending on its design), would in sll likelihood operate in scouring the sand from. the base or apron, resulting in the lowering of tho beach, and the possibility of undermining and clanger to the stability of the Avail. I am convinced from experience that tin: (.fleet of a wall, inter alia, Avould be inimical to the conservation of the beach unless supplemented by groynes, which m mild probably in turn render void the utility of such wall by sanding it up. My recommendation to the Board would theref'.irc be that jetties or groynes (as already indicated) for the restoration of the beach he first constructed, and their effect noted, Wore finally deciding upon the character and design of the esplanade walL Maintenance of Beach and Sand Flats North of St. Clair.—ln order to prevent iurther waste of the Sandhills from seawards, it would be necessary to 'run out groynes from the toe of the sand slope, as suggested in Messrs Mirams and Ussher's report (clause 16), and placed, say, 500 ft apart, so as to raise the beach and push out the high-water mark, preparatory to the erection of wind-brakes and fences for fixing the sand and for the furtherance of plant growth. By the judicious extension of groyne construction along the outer beach, towards Lawyer Head, the sand ridge could be induced to grow, and prevent the wash at high tide from lipping over into the lagoon. But as the formation of such ridge might interfere with the supply of sea-borne drift for the reclamation of the lagoon depression, it might be better left as it is until the. wind-brakes and barriers have done their work. Reclamation and CJonservation.—Area: The acreage included within the space bounded by Victoria street, Forbury road, low-water mark, and an imaginary line drawn from a point on the beach to Onslow House opposite, is estimated by Messrs Mirams and Ussher at eighty acres, and presumed to be the area intended in the first place to be conserved. I would suggest that the depression forming the extension of the lagoon eastwards beyond the above imaginary line be included and added to the above area, for it is apparent that the raising and fixing of the surface westwards of such Repression will tend to maintain it, possibly as a' saltwater lagoon, a contingency which should be avoided tj inducing its reclamation. Levels: The surface levels sought to be attained by the proposed works need not exceed the fineweather height of the bank at the outer beach fronting the lagoon, in order to secure safety from inundation, and render plant life possible. The reclamation of" the lagoon depression, and the growth of marram and other sand-binding grasses, will in all probability he accompanied by a raising pf the outer beach, while the surface generally I may be expected to slowly but continually make. The filling-up of the depressions will also tend to . the increased displacement of salt by comparatively fresh-water, and \ allow of the growth of trees and shrubs | that Avould not otherwise thrive. Barriers: j 1 Avould recommend that durable barriers of spaced palisading or slab fencing be erected across the depressions, commencing, ( as already suggested, at the extrofe east- i ward corner of the lagoon basin and extending their erection westwards" as the sand accumulates. Local experience alone Avill dictate the best directions and distances apart to place them. " Wind-brakes apd Hedges: After the desired levels have been ! attained, the wind-brakes _or hedges' for sand-fixing can be erected, and grass-sQwing or •. planting commenced. These hedges need not be high, but must be close enough j together to fifieker the young plants or j

grasses and prevent tending up. Failure to clothe sand surfaces with grasses is generally due to want of adequate shelter for the plants while young,,or before they have had time to properly root and spread. Scrub of all kinds, hedge-cuttings, and thorns can be Utilised for these hedges. It j is usually found necessary to space them I not wider than 12ft apart, to prevent sand | movement while the seed ig germinating, or the transplanted tufts gaining hold of the sand. Grass-planting, eta.: Tne growth of suitable vegetation after the sands are arrested, should present no difficulties with our abundant rainfall and generally mild coastal temperature, provided discrimination is used in the selection of plants for different degrees of exposure and witness of soil. In the historic fixing of the Landos of Bordeaux, referred to by Mr Hntcheson, Bremonticr divided the area into three zor-es. The first aone (facing the sea) was about 300 yds wide, «vnd planted with mar* ram grass (Arundo aretiaria). * The second zone, of similar width, with brambles, heaths, and creepers, and the inner zono, beyond the influence of salt water, with the maritimo nine (Plnus pinaster). Marram Grass: Of all sand-binding grasses, marram or Gourbet (Arundo arenaria) has proved the hardiest and best sand-binder in temperate climates, and the evidence of its suitability for our needs is manifest in its successful growth at Musselburgh. I would recommend this grass as* the staple sand-binder. It is essential, however, to secure-the proper kind, and in this connection tho letters of Mr Thomas Waugh, attached' to Messrs Minuns's and Usshcr's report, are of interest. Mr Waugh also describes practical methods of sowing and planting the seed and roots. Tree-plant-ing : After the marram or other selected sand-binding grasses have fixed the sands, the planting of picked shrubs and trees could be commenced and extended seawards, as circumstances, such as the growth of sheltering ridge? through the binding ..influences of the grasses, permitted. It should be. clearly understood that tree-plant-ing should follow after the fixing of the surface by sand-binding grasses, and not before. The utilisation of otherwise waste land, increasing the attractiveness of the Domain «x a pleasure resort, the provision of a sand-covering more permanent than grass, may 1* considered the principal objects of tree-planting. But it is absolutely necessary to successful forestry that the sand be fixed, so that, it may not choke and the young trees. San drift in the neighborhood of plantations must hf prevented and avoided by the growth of grass. Tho sanding-up 'of the fringe of the bush or forest near the sea bv the sand set free through the destruction of tho grasses, is common throughout the colonies, ;md it is a familiar sight to see a few dry twigs on a sand dune, marking the grave of some tree, gi-een but a few months before. Prohibited Areas: It is recommended that the Sandhills and flats, with the exception of the outer beach, be absolutely protected from traffic wherever sand-fixing and grass-planting operations are in progress. * The Sandhills, might be specially guarded by a system of barbed wire fences or entangzlementss, which have proved elsewhere efficient protection against invasion, enabling the native sand grasses to gain ground, as well as foster the growth of shrubs and trees planted thereon. Nurseries.- In order that a supply of plants may be available when wanted, and their suitability to climate and situation tested, it is suggested that plots of ground in chosen situations be hid of as nurseries. Standard varieties of sand-loving grasses and plants could there be propagated, and the adaptability of native grasses, heaths, shrubs, etc., and of various Australian and foreign plants tested. Recommendations. —In order that the Board may possess some general scheme, embodying the extent and scope of their probable operations, the following summary of recommendations is now submitted, together with notes on the future management 'of the Domain, that may prove of v:»lue to the Board. The proposed "works are arranged in the order of their priority. (1) Construction of experimental groyne opposite St. Clair. (For particulars see addendum, page 16.) (2) Complete survey of Ocean Beach Domain and St. Clair, embracing current observations and collection of all duta necessary for locating groynes and walls, Avith cross sections at frequent intervals for future comparison and reference. (3) Construction of jetty groyne for the protection of the beach at St. Clair. (4) Construction of pontoon or rough timber crib groynes for building up the beach opposite the Sandhills eastwards of St. Clair. (5) Establishment of nurseries for the propagation of sand-loving grasses and plants, and for experiments as to the suitability of different plants for various aspects and degrees of saitness of soil. A list of various sand-loving grasses and plants is appended. (6) Esplanade at St. Clair can be proceeded with when the effect of the proposed groyne in raising the beach has been noted, and the character, either as a retaining wall only, or as a sea defence, determined. (7) Sand barriers: Erection of barriers for reclamation of depressions, and wind-breaks and artificial hedges for the temporary fixing of the sand preparatory to grass-planting. (8) Management of the Domain : In the conduct of operations, under the Board's control it will be recognised that, while their first attention mask be directed to the prevention of further sea encroachments, their ,ultimate aim will no doubt be the conversion of the Domain into a people's park'by methods rnajogous to those The economical success of such methods must depend largely upon the attention and judgment of the Board's employes, as much of the work of conservation will be on empirical lines, and details of procedure dictated by the experience gained as the* work proceeds. Curator:. I would suggest, therefore, that the direction of sand-fixing and tree-plant-ing operations be placed in the hfwids of a. gentleman eminent in botanical science, etc., who would be willing to act ag curator, and to wjipm the manager or local officer of the Board could look to for guidance in the above important part of his duties. Manager: It is ajsp suggested a manager be appointed, possessing a knowledge of landscape gardening and 'forestry, and powers of initiation and observation. The duties of suph an officer could include the charge of the Domain nurseries, supervision of sand-fixing and grassplanting, and acting as ranger and prosecuting officer-in the enforcement of the by-laws, rules, and. regulations necessary for the maintepance and protection of the Board's property. Expenditure.—As the Board might desire to possess some idea of the probable exxpenditure required in performing the functions of maintenance and conservation of the lines herein suggested, I have endeavored to approximate the cost of continuous operations and management, as well as the cost of non-recurring works, over a period of five years from the initiation of such works. The annual cost for management and labor extending" over the above period," including manager, honorarium to curator, office expenses, labor, maintenance, contingencies, js estimated to be—'for the first year £6OO, second year £6OO, third year £640, fourth year £-735, fifth year, £750; grand total for five years, £5,325. The total estimated annual expenditure for the period of five years, including surveys, jetty groyne at St. Clair, groynes opposite Sandhills, esplanade at St. Clair, sand barriers, wire fences and entanglenjents, nurseries, seeds and plants', management and "labor, is:' First "year £IJBOO, second year' £3,000, third year fourth year £1,435, fifth'year £9OO. Total hon'-recurring expenditure, £5jl00; managpmept and labor, per statement, £3,325; total expenditure for fiye years, £8,425; extra fpr waft of esplanade, constructed in ceinent concrete (as sea defence), £1,200; extra for wall in timber, £310; - List of Sand-Lpving Plants and Grasses. —For sea frontage: Marram grass or gourbet (Arundo arenara), sea lyme (Elyraus arenarins), sea wheat (Triticum junceum}, giant or land lupin, Australian coast titri (Legtcspernum branch-spreading plagianthus (Phgjantjme divaricatus). For inner area: scrub (Leptospermsm scoparinm), Tas- :

NeV' JJeilMtd. brana^fltofcasSAfcJfralis). sheotk(CaauarJna sHeo«k {Oam- *«*» ..Mifepsa}, wattto'pmch a* acacia, daidbfcte,; mfelany afid P™ B ' ,tf?inus pinaster), kand-lovi&g euca» iypU, heaths and.,aMp«B.