陳富強(qiáng)

麗水通濟(jì)堰，建成已逾1500年，入選世界灌溉工程遺產(chǎn)。通濟(jì)堰上建有一座立體交叉石函引水橋，俗稱“三洞橋”。曾有一位名叫福田的日本人站在“三洞橋”上贊嘆說：“當(dāng)世界上尚無立交橋時(shí)，中國人已在這山鄉(xiāng)建造了水的立交橋?！?/span>

南宋名臣范成大入處州（今浙江麗水），是乾道三年（公元1167年），距今逾850年。由此再上溯至南朝蕭梁天監(jiān)四年（公元505年），逾660年，兩數(shù)相加，逾1500年。這是麗水通濟(jì)堰的年齡。

梳理中國的水利設(shè)施，如果遺漏通濟(jì)堰，通常是一個(gè)常識(shí)性錯(cuò)誤。雖然我沒有十分豐富的水利方面學(xué)識(shí)，但對(duì)于中國最著名的水利設(shè)施，我還是大致能說出一二。我研究電力多年，而水利總是和電力連在一起。水電一家，是近現(xiàn)代史上最明顯不過的孿生雙胞，密不可分，所謂無水不成電。當(dāng)然，古代的水利設(shè)施，則更側(cè)重于治水，比如新疆的坎爾井，成都的都江堰，麗水的通濟(jì)堰。

但我確實(shí)犯了一個(gè)常識(shí)性的甚至是不可原諒的錯(cuò)誤。多年以前，我參與《中國治水史詩》的創(chuàng)作，這部堪稱中國治水百科全書的巨作，匯集了當(dāng)代近百名作家的智慧。我主筆浙江篇。從大禹治水的傳說寫起，由鑒湖而至蘇東坡疏浚西湖，再由京杭大運(yùn)河南端而循錢塘江源頭順流而下，寫到了千島湖的形成，富春江的山水。凡浙江水利，皆一一收錄。但我居然將浙江重要的通濟(jì)堰放在一邊，在成文時(shí)，竟然遺忘了。直至?xí)霭?，我還沒有意識(shí)到這個(gè)重大失誤。

數(shù)月后，一封來自麗水的手寫書信出現(xiàn)在我的案頭。自從有了網(wǎng)絡(luò)，我已經(jīng)很少接觸到類似書信。我展開一閱，居然讀出一身冷汗。此信作者是麗水一位很有聲望的老作家，名叫吳剛戟。吳老先生在信中指出，既然寫浙江水利，怎么可以不寫通濟(jì)堰？我從吳老先生的字里行間，能感受到他的失望，甚至氣憤。冷靜思想，我在寫作過程中，的確沒有把通濟(jì)堰列上重點(diǎn)，以至于在最后成稿時(shí)，將其遺漏。一方面是我缺乏對(duì)通濟(jì)堰重要性的認(rèn)識(shí)，另一方面，也可見自己治學(xué)的不夠嚴(yán)謹(jǐn)。我當(dāng)即給吳老先生回函，除了檢討，我也向他保證，會(huì)修訂我主筆的浙江治水篇，盡可能彌補(bǔ)這個(gè)缺憾。

后來，雖然有關(guān)通濟(jì)堰的內(nèi)容，我作了增補(bǔ)，并且在發(fā)表和收錄其他文本時(shí)，用的是完整篇章，但這個(gè)遺憾卻一直壓在我的心頭，難以排解。且不說通濟(jì)堰的歷史可與都江堰媲美，僅世界上最早的拱形壩體這個(gè)記錄，就足以說明通濟(jì)堰在世界水利史上的不同凡響。國外最早的拱壩是西班牙人建于16世紀(jì)的愛爾其拱壩和意大利人建于1612年的邦達(dá)爾多拱壩，而始建于公元505年的通濟(jì)堰比它們的歷史要早1000多年。所以，后來通濟(jì)堰能入選世界灌溉工程遺產(chǎn)，也變得理所當(dāng)然。

在我主筆浙江治水篇10年后，我第一次見到通濟(jì)堰真容。雖然稍晚了一些，但相比古堰1500年的歷史，10年不過滄海一粟。

從石函引水橋，過文昌閣，向古堰行500米，即到通濟(jì)堰壩體。石函引水橋是一座水上立交橋，建造的起因是距離古堰拱形大壩500米處有一條名為泉坑的山坑，其水橫貫通濟(jì)堰渠道，每遇山洪暴發(fā)就挾帶大量沙礫和卵石沖泄而下，淤塞渠道，使堰水受阻，需經(jīng)常疏通。面對(duì)如此水患，很久以來似乎沒有很好的根除方法。直到北宋政和元年，時(shí)任知縣王褆按邑人葉秉心的建議，在通濟(jì)堰上建造了一座立體交叉石函引水橋，俗稱“三洞橋”。引泉坑水從橋面上通過，進(jìn)入甌江，渠水從橋下穿流，兩者互不相擾。由此避免了坑水的沙石堵塞堰渠，使渠水暢通無阻，不需年年疏導(dǎo)，真有“石函一成……五十年無工役之?dāng)_”的功效?？梢姰?dāng)時(shí)設(shè)計(jì)、建筑水平已經(jīng)十分高超。據(jù)稱，曾有一位名叫福田的日本人站在“三洞橋”上贊嘆說：“當(dāng)世界上尚無立交橋時(shí)，中國人已在這山鄉(xiāng)建造了水的立交橋”。

護(hù)堤的古樟群堪稱通濟(jì)堰一景。這些香樟樹，樹齡通常有數(shù)百年之久。其中一棵已枯死，但神奇的是，如果不經(jīng)點(diǎn)撥，很難看出這棵古樟已無綠葉，因?yàn)樵谒膶?duì)岸，也有一棵同樣古老的香樟，那棵樹依舊枝繁葉茂，兩樹的枝葉在水渠上空相觸，茂密的綠葉覆蓋住枯樹的枝葉，倘若不加細(xì)辨，很難區(qū)分。這些樟樹蒼勁挺拔，遮天蓋地，扎根于泥土之下，盤根錯(cuò)節(jié)，為護(hù)堰盡畢生之力。而樟樹散發(fā)出來的特有清香，有時(shí)間的味道，繞百年而不散。

通濟(jì)堰的修建，在古代算得上大工程，參與人無數(shù)，但給后世留下的史料，經(jīng)過民間千年口口相傳，其實(shí)并不豐富。在堰口堤壩上，豎有詹司馬、南司馬石像，“二司馬”是最初的建造者。石像邊上的碑文，簡述“二司馬”建堰史。南朝梁天監(jiān)四年，即公元505年，詹司馬奏請(qǐng)?jiān)谒申幭c大溪江合流處筑堰壩，朝廷又遣南司馬共治其事，首創(chuàng)拱壩形式得以建成，匯松陰溪水入堰渠，渠道自大壩至白橋注入大溪，全長23公里，灌溉農(nóng)田2.5萬畝。此后，又有郡人參政何澹，民間也稱何丞相，奏請(qǐng)朝廷“為圖久遠(yuǎn)，不費(fèi)修筑”，調(diào)兵3000人，歷時(shí)3年重建通濟(jì)堰，大壩由原來的木筱結(jié)構(gòu)改為結(jié)石結(jié)構(gòu)。為使其永固，并造鐵爐36座，用鐵水灌入石壩縫隙中，使大壩牢不可摧。

通濟(jì)堰名的出現(xiàn)，幾乎是在古堰建造完成600多年以后。南宋紹興八年，也就是公元1138年，據(jù)沈國琛《通濟(jì)堰》載：“南渡后，汶上趙學(xué)老分宰縣事，深羨是堰之利民勘博也，賜名‘通濟(jì)以美之……”從此，通濟(jì)古堰以其卓然的姿態(tài)，立碧湖平原之上，讓甌江兩岸風(fēng)調(diào)雨順，再無水患之憂。

時(shí)間過去1500年，除“二司馬”、何澹，與通濟(jì)堰關(guān)系非同一般的還有南宋詩人范成大。范氏以田園詩留名，一生創(chuàng)作詩歌近2000首，其中大多為田園詩。但頗為詭奇的是范成大任處州（即如今的麗水），任職時(shí)間只有短短9個(gè)月，卻成為處州史上功績最為卓著的一位知府。而且，在范成大浩瀚的田園詩里，居然找不到與麗水有關(guān)的田園詩。不過，他與通濟(jì)堰的不解之緣，卻讓他以另一種書寫方式留下不朽詩篇。

通濟(jì)堰自古留有堰史、堰規(guī)，對(duì)筑堰、護(hù)堰有功者，均刻碑立于世。宋代范成大、明代湯顯祖等曾任職處州的官員都曾經(jīng)為通濟(jì)堰樹碑撰文。其中最著名的當(dāng)系范成大《通濟(jì)堰規(guī)》碑和南宋初年《通濟(jì)堰圖》碑及水系圖碑。這些都是研究通濟(jì)堰歷史和管理制度的最珍貴水利文物和實(shí)物資料，不可多得。

范成大任職處州期間，主持修整通濟(jì)堰。更為重要的是，他親自制定和撰寫堰規(guī)，立碑勒石，“文意賅簡，書逼蘇黃”，手跡猶在。他興工3個(gè)月修復(fù)通濟(jì)堰，并揮毫?xí)鴮憽锻?jì)堰規(guī)》20條，記言14行，立碑以告來者。此《堰規(guī)》已經(jīng)沿用了數(shù)百年。《括蒼金石志》稱：“范公條規(guī)，百世遵守可也”，可見其價(jià)值所在。

至于范成大為何沒有在處州留下他的田園詩，麗水博物館張慧琴曾撰文分析。張文稱：范成大乾道三年（1167年）十二月知處州，真正赴任是在乾道四年七月，乾道五年五月離任，因此在處州只有9個(gè)月。時(shí)間雖短暫，但為民辦的實(shí)事甚多。如創(chuàng)義役，以解百姓當(dāng)差的后顧之憂;修復(fù)通濟(jì)堰，使民享其利;上《論不舉子疏》，置?？铕B(yǎng)孤兒，并為民請(qǐng)命，減浙東丁錢等;同時(shí)，新建處州帶郭浮橋——平政橋，此橋幾經(jīng)重修，在1984年小水門大橋建成前，一直是府城南北的唯一通道。其中創(chuàng)義役、修復(fù)通濟(jì)堰在《宋史》本傳中均有詳細(xì)的記載。正是因?yàn)橛小皯n稼穡、憫老農(nóng)”的憂民意識(shí)，詩人很想通過自己的吏治去為民辦事，對(duì)于田園風(fēng)光自然無暇顧及了。

然而，范成大留在通濟(jì)堰的《堰規(guī)》，顯然是更有浩然之氣的田園詩。

我去麗水，正值雨季，連續(xù)數(shù)日密雨，從上游下泄的流水，已淹沒古堰，只見微黃的流水，在堰壩之前匯成一個(gè)安靜的湖，等到漫過壩體，向下游浩蕩而去時(shí)，就是激流。激流之上，露出水面的，是兩岸青山，和堰下的綠洲。其中一處小洲，流水溢過樹叢，疊石不動(dòng)，不由讓人想起宋代晁公溯描寫通濟(jì)堰的詩句：“橫江三百丈，遙見石嶙峋。”

沿通濟(jì)堰順流而下，兩岸風(fēng)景如畫。其地天生麗質(zhì)，也就有了古堰畫鄉(xiāng)的美名。坐船從古堰一側(cè)渡向?qū)Π?，埠頭一棵樟樹，堪稱樹王。一樹成林，遮住一個(gè)不小的廣場，使烈日之下，也有了清涼之所。而在樹旁的飯館，如能吃上一尾甌江的魚，則更好。坐于窗下，可眺甌江，遠(yuǎn)山如黛，幾葉帆影，疏影橫斜過窗前。

從遠(yuǎn)處眺望通濟(jì)堰，我想起曾經(jīng)主筆創(chuàng)作的浙江治水篇，有一種巨大的缺憾終于彌補(bǔ)的欣慰。同為宋，北宋有蘇軾，疏浚西湖，因湖上一堤，為蘇堤;南宋有范成大，西湖西行五百里，修古堰通濟(jì)，而名留青史。他們都是詩人，都以詩名流芳，但都以改造或修繕?biāo)O(shè)施而為民得利。一南一北，一前一后，異曲同工，“天下同歸而殊途，一致而百慮”，說的就是范成大和蘇東坡吧。

I made an unforgivable mistake years ago when I was in charge of writing a volume tracing Zhejiangs accomplished water control systems since very ancient times. I somehow failed to mention the Tongji Weir in Lishui in southern Zhejiang. The volume was part of a national collection of prominent water control systems in Chinese history. The collection came out in November 2011. A few months later， I received a letter from Wu Guangji， a prominent writer based in Lishui. He scolded me for my omission of the ancient irrigation system in Lishui. A cold sweat broke out in me and I shuddered at my glaring oversight when I was reading his letter.?

I apologized to him and promised to correct the dire mistake in a new edition of the volume. I was able to correct the mistake by adding a full-length essay on the ancient water control miracle in the new edition， but the oversight has been haunting me.

The Tongji Weir is a vast water control system first built in 505 AD and expanded， upgraded and maintained in the subsequent centuries. The curved low dam is 275 meters long， 25 meters wide and 2.5 meters high. It saves rainfalls in an area of 3，150 square kilometers in its upper streams. That is， it diverts about 200，000 cubic meters daily into ponds and reservoirs through a vast network of irrigation canals in the region.

In 2001， the weir system was inscribed on a national list and placed under protection of the state government. In 2014， it was honorably designated as a World Irrigation Project Heritage.

A temple stands near the weir in honor of the ancients who contributed to the building and maintaining of the water control system. Of the ancient relics are two stone statues in honor of Zhan Sima and Nan Sima. Zhan and Nan were two government officials in charge of building the original weir and a 23-kilometer canal which irrigated 16.6-square-kilometer farmlands. Later the low dam was restructured into a stone system strengthened with rocks all sealed off with iron poured into the dam. In 1138， which was about 600 years after the system first came into function， the weir system was officially called Tongji， which literally means bringing comprehensive benefits to people.

The Tongji Weir is well preserved in many ways. One of the outstanding features of the water control system is that it has maintained a complete set of stone steles created over the past dynasties. One of the steles， created by Fan Chengda （1126-1193） of the Southern Song Dynasty （1127-1279）， bears a complete text that documents 20 must-do rules for administration and maintenance of the weir. Created in the early years of the Southern Song， another stele presents a map of the weir system

Fan Chengda is celebrated in the history of Chinese literature for his nature poems which number over 2，000. He served as a local governor where the Tongji Weir system was for only nine months， but wrote no poems there. Instead， he was busily engaged in his administrative duties. He spent three months masterminding and carrying out a restoration project of the Tongji Weir system. Moreover， he conducted a number of projects that benefited local people a great deal. For example， he set up an orphanage system. He carried out a tax reduction. He had a bridge built. The bridge， which functioned well up to 1984， was a key part of the local road system.

Today， the well preserved ancient weir is at the core of a well known tourist attraction in Lishui. The landscape around the ancient weir is picturesque and there is a colony of artists based in a nearby waterside town. Artists and photographers gravitate toward the colony and fascinate themselves with the views of the natural beauty around them.

It was not until about ten years after I had penned an essay about the Tongji Weir that I first visited the ancient system. My visit occurred in a rainy season. After a few days of rain， the low dam was submerged by waters from the upper stream， forming a quiet lake. Waters cascaded over the low dam， flanked by emerald peaks on both sides. A small shoal， covered with a stand of trees， tried to resist the overflowing currents. The trees swayed， but the rocks there didnt budge an inch. A ferry pier by the weir was covered by a giant shady camphor tree， which was very ancient. A restaurant by the camphor tree was the right place to enjoy a fish dinner and enjoy the sight of the river and the peaks.